diff --git a/.travis.yml b/.travis.yml
index e3bdf2af..d3c4ff63 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -15,8 +15,8 @@ before_install:
   - chmod a+x ./gradlew
 script:
   # test using maven
-  #- mvn test
+  - mvn test
   # test using gradle
-  - gradle test
+  # - gradle test
   # test using sbt 
   # - sbt test
diff --git a/Makefile b/Makefile
deleted file mode 100644
index 9f47ce20..00000000
--- a/Makefile
+++ /dev/null
@@ -1,61 +0,0 @@
-VERSION := $(shell cat VERSION)
-
-.PHONY: build
-build:
-	find . -mindepth 1 -maxdepth 1 -not -name Makefile -not -name .git -not -name .gitignore -exec rm -Rf {} ';'
-	echo $(VERSION) > VERSION
-	curl https://raw.githubusercontent.com/argoproj/argo/$(VERSION)/api/openapi-spec/swagger.json | sed 's/io.argoproj.workflow.v1alpha1.//' | sed 's/io.k8s.api.core.v1.//' | sed 's/io.k8s.apimachinery.pkg.apis.meta.v1.//' > swagger.json
-	docker run --rm -v `pwd`:/wd openapitools/openapi-generator-cli:v4.3.1 \
-		generate \
-		-i /wd/swagger.json \
-		-g java \
-		-o /wd \
-		-p hideGenerationTimestamp=true \
-		-p dateLibrary=joda \
-		--api-package io.argoproj.workflow.apis \
-		--invoker-package io.argoproj.workflow \
-		--model-package io.argoproj.workflow.models \
-		--skip-validate-spec \
-		--group-id io.argoproj.workflow \
-		--artifact-id argo-client-java \
-		--artifact-version $(VERSION) \
-		--import-mappings Time=org.joda.time.DateTime \
-		--import-mappings Affinity=io.kubernetes.client.openapi.models.V1Affinity \
-		--import-mappings ConfigMapKeySelector=io.kubernetes.client.openapi.models.V1ConfigMapKeySelector \
-		--import-mappings Container=io.kubernetes.client.openapi.models.V1Container \
-		--import-mappings ContainerPort=io.kubernetes.client.openapi.models.V1ContainerPort \
-		--import-mappings EnvFromSource=io.kubernetes.client.openapi.models.V1EnvFromSource \
-		--import-mappings EnvVar=io.kubernetes.client.openapi.models.V1EnvVar \
-		--import-mappings HostAlias=io.kubernetes.client.openapi.models.V1HostAlias \
-		--import-mappings Lifecycle=io.kubernetes.client.openapi.models.V1Lifecycle \
-		--import-mappings ListMeta=io.kubernetes.client.openapi.models.V1ListMeta \
-		--import-mappings LocalObjectReference=io.kubernetes.client.openapi.models.V1LocalObjectReference \
-		--import-mappings ObjectMeta=io.kubernetes.client.openapi.models.V1ObjectMeta \
-		--import-mappings ObjectReference=io.kubernetes.client.openapi.models.V1ObjectReference \
-		--import-mappings PersistentVolumeClaim=io.kubernetes.client.openapi.models.V1PersistentVolumeClaim \
-		--import-mappings PodDisruptionBudgetSpec=io.kubernetes.client.openapi.models.V1beta1PodDisruptionBudgetSpec \
-		--import-mappings PodDNSConfig=io.kubernetes.client.openapi.models.V1PodDNSConfig \
-		--import-mappings PodSecurityContext=io.kubernetes.client.openapi.models.V1PodSecurityContext \
-		--import-mappings Probe=io.kubernetes.client.openapi.models.V1Probe \
-		--import-mappings ResourceRequirements=io.kubernetes.client.openapi.models.V1ResourceRequirements \
-		--import-mappings SecretKeySelector=io.kubernetes.client.openapi.models.V1SecretKeySelector \
-		--import-mappings SecurityContext=io.kubernetes.client.openapi.models.V1SecurityContext \
-		--import-mappings Toleration=io.kubernetes.client.openapi.models.V1Toleration \
-		--import-mappings Volume=io.kubernetes.client.openapi.models.V1Volume \
-		--import-mappings VolumeDevice=io.kubernetes.client.openapi.models.V1VolumeDevice \
-		--import-mappings VolumeMount=io.kubernetes.client.openapi.models.V1VolumeMount \
-		--generate-alias-as-model
-	# add the io.kubernetes:java-client to the deps
-	sed 's/<dependencies>/<dependencies><dependency><groupId>io.kubernetes<\/groupId><artifactId>client-java<\/artifactId><version>9.0.2<\/version><\/dependency>/g' pom.xml > tmp && mv tmp pom.xml
-	docker run -v ~/.m2:/root/.m2 -v `pwd`:/wd -w /wd maven:3-openjdk-8 \
-		mvn install -DskipTests -Dmaven.javadoc.skip
-	git add .
-	git commit -m 'Updated to $(VERSION)' || git diff --exit-code
-	git tag -f $(VERSION)
-
-.PHONY: publish
-publish: build
-	# https://help.github.com/en/packages/using-github-packages-with-your-projects-ecosystem/configuring-apache-maven-for-use-with-github-packages
-	docker run -v ~/.m2:/root/.m2 -v `pwd`:/wd -w /wd maven:3-openjdk-8 \
-		mvn deploy -DskipTests -Dmaven.javadoc.skip -DaltDeploymentRepository=github::default::https://maven.pkg.github.com/argoproj-labs/argo-client-java
-	git push --tags
diff --git a/build.gradle b/build.gradle
deleted file mode 100644
index f429222c..00000000
--- a/build.gradle
+++ /dev/null
@@ -1,114 +0,0 @@
-apply plugin: 'idea'
-apply plugin: 'eclipse'
-apply plugin: 'java'
-
-group = 'io.argoproj.workflow'
-version = 'v3.1.0'
-
-buildscript {
-    repositories {
-        maven { url "https://repo1.maven.org/maven2" }
-        jcenter()
-    }
-    dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.+'
-        classpath 'com.github.dcendents:android-maven-gradle-plugin:1.5'
-    }
-}
-
-repositories {
-    jcenter()
-}
-sourceSets {
-    main.java.srcDirs = ['src/main/java']
-}
-
-if(hasProperty('target') && target == 'android') {
-
-    apply plugin: 'com.android.library'
-    apply plugin: 'com.github.dcendents.android-maven'
-
-    android {
-        compileSdkVersion 25
-        buildToolsVersion '25.0.2'
-        defaultConfig {
-            minSdkVersion 14
-            targetSdkVersion 25
-        }
-        compileOptions {
-            sourceCompatibility JavaVersion.VERSION_1_7
-            targetCompatibility JavaVersion.VERSION_1_7
-        }
-
-        // Rename the aar correctly
-        libraryVariants.all { variant ->
-            variant.outputs.each { output ->
-                def outputFile = output.outputFile
-                if (outputFile != null && outputFile.name.endsWith('.aar')) {
-                    def fileName = "${project.name}-${variant.baseName}-${version}.aar"
-                    output.outputFile = new File(outputFile.parent, fileName)
-                }
-            }
-        }
-
-        dependencies {
-            provided 'javax.annotation:javax.annotation-api:1.3.2'
-        }
-    }
-
-    afterEvaluate {
-        android.libraryVariants.all { variant ->
-            def task = project.tasks.create "jar${variant.name.capitalize()}", Jar
-            task.description = "Create jar artifact for ${variant.name}"
-            task.dependsOn variant.javaCompile
-            task.from variant.javaCompile.destinationDir
-            task.destinationDir = project.file("${project.buildDir}/outputs/jar")
-            task.archiveName = "${project.name}-${variant.baseName}-${version}.jar"
-            artifacts.add('archives', task);
-        }
-    }
-
-    task sourcesJar(type: Jar) {
-        from android.sourceSets.main.java.srcDirs
-        classifier = 'sources'
-    }
-
-    artifacts {
-        archives sourcesJar
-    }
-
-} else {
-
-    apply plugin: 'java'
-    apply plugin: 'maven'
-
-    sourceCompatibility = JavaVersion.VERSION_1_7
-    targetCompatibility = JavaVersion.VERSION_1_7
-
-    install {
-        repositories.mavenInstaller {
-            pom.artifactId = 'argo-client-java'
-        }
-    }
-
-    task execute(type:JavaExec) {
-       main = System.getProperty('mainClass')
-       classpath = sourceSets.main.runtimeClasspath
-    }
-}
-
-dependencies {
-    compile 'io.swagger:swagger-annotations:1.5.24'
-    compile "com.google.code.findbugs:jsr305:3.0.2"
-    compile 'com.squareup.okhttp3:okhttp:3.14.7'
-    compile 'com.squareup.okhttp3:logging-interceptor:3.14.7'
-    compile 'com.google.code.gson:gson:2.8.6'
-    compile 'io.gsonfire:gson-fire:1.8.4'
-    compile group: 'org.apache.commons', name: 'commons-lang3', version: '3.10'
-    compile 'joda-time:joda-time:2.9.9'
-    testCompile 'junit:junit:4.13'
-}
-
-javadoc {
-    options.tags = [ "http.response.details:a:Http Response Details" ]
-}
diff --git a/build.sbt b/build.sbt
deleted file mode 100644
index 3f8211b8..00000000
--- a/build.sbt
+++ /dev/null
@@ -1,24 +0,0 @@
-lazy val root = (project in file(".")).
-  settings(
-    organization := "io.argoproj.workflow",
-    name := "argo-client-java",
-    version := "v3.1.0",
-    scalaVersion := "2.11.4",
-    scalacOptions ++= Seq("-feature"),
-    javacOptions in compile ++= Seq("-Xlint:deprecation"),
-    publishArtifact in (Compile, packageDoc) := false,
-    resolvers += Resolver.mavenLocal,
-    libraryDependencies ++= Seq(
-      "io.swagger" % "swagger-annotations" % "1.5.24",
-      "com.squareup.okhttp3" % "okhttp" % "3.14.7",
-      "com.squareup.okhttp3" % "logging-interceptor" % "3.14.7",
-      "com.google.code.gson" % "gson" % "2.8.6",
-      "org.apache.commons" % "commons-lang3" % "3.10",
-      "joda-time" % "joda-time" % "2.9.9" % "compile",
-      "io.gsonfire" % "gson-fire" % "1.8.3" % "compile",
-      "javax.annotation" % "javax.annotation-api" % "1.3.2" % "compile",
-      "com.google.code.findbugs" % "jsr305" % "3.0.2" % "compile",
-      "junit" % "junit" % "4.13" % "test",
-      "com.novocode" % "junit-interface" % "0.10" % "test"
-    )
-  )
diff --git a/gradle.properties b/gradle.properties
deleted file mode 100644
index 05644f07..00000000
--- a/gradle.properties
+++ /dev/null
@@ -1,2 +0,0 @@
-# Uncomment to build for Android
-#target = android
\ No newline at end of file
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
deleted file mode 100644
index cc4fdc29..00000000
Binary files a/gradle/wrapper/gradle-wrapper.jar and /dev/null differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
deleted file mode 100644
index 94920145..00000000
--- a/gradle/wrapper/gradle-wrapper.properties
+++ /dev/null
@@ -1,5 +0,0 @@
-distributionBase=GRADLE_USER_HOME
-distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.0.1-bin.zip
-zipStoreBase=GRADLE_USER_HOME
-zipStorePath=wrapper/dists
diff --git a/gradlew b/gradlew
deleted file mode 100644
index 2fe81a7d..00000000
--- a/gradlew
+++ /dev/null
@@ -1,183 +0,0 @@
-#!/usr/bin/env sh
-
-#
-# Copyright 2015 the original author or authors.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#      https://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-#
-
-##############################################################################
-##
-##  Gradle start up script for UN*X
-##
-##############################################################################
-
-# Attempt to set APP_HOME
-# Resolve links: $0 may be a link
-PRG="$0"
-# Need this for relative symlinks.
-while [ -h "$PRG" ] ; do
-    ls=`ls -ld "$PRG"`
-    link=`expr "$ls" : '.*-> \(.*\)$'`
-    if expr "$link" : '/.*' > /dev/null; then
-        PRG="$link"
-    else
-        PRG=`dirname "$PRG"`"/$link"
-    fi
-done
-SAVED="`pwd`"
-cd "`dirname \"$PRG\"`/" >/dev/null
-APP_HOME="`pwd -P`"
-cd "$SAVED" >/dev/null
-
-APP_NAME="Gradle"
-APP_BASE_NAME=`basename "$0"`
-
-# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
-
-# Use the maximum available, or set MAX_FD != -1 to use that value.
-MAX_FD="maximum"
-
-warn () {
-    echo "$*"
-}
-
-die () {
-    echo
-    echo "$*"
-    echo
-    exit 1
-}
-
-# OS specific support (must be 'true' or 'false').
-cygwin=false
-msys=false
-darwin=false
-nonstop=false
-case "`uname`" in
-  CYGWIN* )
-    cygwin=true
-    ;;
-  Darwin* )
-    darwin=true
-    ;;
-  MINGW* )
-    msys=true
-    ;;
-  NONSTOP* )
-    nonstop=true
-    ;;
-esac
-
-CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
-
-# Determine the Java command to use to start the JVM.
-if [ -n "$JAVA_HOME" ] ; then
-    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
-        # IBM's JDK on AIX uses strange locations for the executables
-        JAVACMD="$JAVA_HOME/jre/sh/java"
-    else
-        JAVACMD="$JAVA_HOME/bin/java"
-    fi
-    if [ ! -x "$JAVACMD" ] ; then
-        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
-
-Please set the JAVA_HOME variable in your environment to match the
-location of your Java installation."
-    fi
-else
-    JAVACMD="java"
-    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
-
-Please set the JAVA_HOME variable in your environment to match the
-location of your Java installation."
-fi
-
-# Increase the maximum file descriptors if we can.
-if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
-    MAX_FD_LIMIT=`ulimit -H -n`
-    if [ $? -eq 0 ] ; then
-        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
-            MAX_FD="$MAX_FD_LIMIT"
-        fi
-        ulimit -n $MAX_FD
-        if [ $? -ne 0 ] ; then
-            warn "Could not set maximum file descriptor limit: $MAX_FD"
-        fi
-    else
-        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
-    fi
-fi
-
-# For Darwin, add options to specify how the application appears in the dock
-if $darwin; then
-    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
-fi
-
-# For Cygwin or MSYS, switch paths to Windows format before running java
-if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
-    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
-    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
-    JAVACMD=`cygpath --unix "$JAVACMD"`
-
-    # We build the pattern for arguments to be converted via cygpath
-    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
-    SEP=""
-    for dir in $ROOTDIRSRAW ; do
-        ROOTDIRS="$ROOTDIRS$SEP$dir"
-        SEP="|"
-    done
-    OURCYGPATTERN="(^($ROOTDIRS))"
-    # Add a user-defined pattern to the cygpath arguments
-    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
-        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
-    fi
-    # Now convert the arguments - kludge to limit ourselves to /bin/sh
-    i=0
-    for arg in "$@" ; do
-        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
-        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
-
-        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
-            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
-        else
-            eval `echo args$i`="\"$arg\""
-        fi
-        i=`expr $i + 1`
-    done
-    case $i in
-        0) set -- ;;
-        1) set -- "$args0" ;;
-        2) set -- "$args0" "$args1" ;;
-        3) set -- "$args0" "$args1" "$args2" ;;
-        4) set -- "$args0" "$args1" "$args2" "$args3" ;;
-        5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
-        6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
-        7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
-        8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
-        9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
-    esac
-fi
-
-# Escape application args
-save () {
-    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
-    echo " "
-}
-APP_ARGS=`save "$@"`
-
-# Collect all arguments for the java command, following the shell quoting and substitution rules
-eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
-
-exec "$JAVACMD" "$@"
diff --git a/gradlew.bat b/gradlew.bat
deleted file mode 100644
index 9618d8d9..00000000
--- a/gradlew.bat
+++ /dev/null
@@ -1,100 +0,0 @@
-@rem
-@rem Copyright 2015 the original author or authors.
-@rem
-@rem Licensed under the Apache License, Version 2.0 (the "License");
-@rem you may not use this file except in compliance with the License.
-@rem You may obtain a copy of the License at
-@rem
-@rem      https://www.apache.org/licenses/LICENSE-2.0
-@rem
-@rem Unless required by applicable law or agreed to in writing, software
-@rem distributed under the License is distributed on an "AS IS" BASIS,
-@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-@rem See the License for the specific language governing permissions and
-@rem limitations under the License.
-@rem
-
-@if "%DEBUG%" == "" @echo off
-@rem ##########################################################################
-@rem
-@rem  Gradle startup script for Windows
-@rem
-@rem ##########################################################################
-
-@rem Set local scope for the variables with windows NT shell
-if "%OS%"=="Windows_NT" setlocal
-
-set DIRNAME=%~dp0
-if "%DIRNAME%" == "" set DIRNAME=.
-set APP_BASE_NAME=%~n0
-set APP_HOME=%DIRNAME%
-
-@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
-
-@rem Find java.exe
-if defined JAVA_HOME goto findJavaFromJavaHome
-
-set JAVA_EXE=java.exe
-%JAVA_EXE% -version >NUL 2>&1
-if "%ERRORLEVEL%" == "0" goto init
-
-echo.
-echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
-echo.
-echo Please set the JAVA_HOME variable in your environment to match the
-echo location of your Java installation.
-
-goto fail
-
-:findJavaFromJavaHome
-set JAVA_HOME=%JAVA_HOME:"=%
-set JAVA_EXE=%JAVA_HOME%/bin/java.exe
-
-if exist "%JAVA_EXE%" goto init
-
-echo.
-echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
-echo.
-echo Please set the JAVA_HOME variable in your environment to match the
-echo location of your Java installation.
-
-goto fail
-
-:init
-@rem Get command-line arguments, handling Windows variants
-
-if not "%OS%" == "Windows_NT" goto win9xME_args
-
-:win9xME_args
-@rem Slurp the command line arguments.
-set CMD_LINE_ARGS=
-set _SKIP=2
-
-:win9xME_args_slurp
-if "x%~1" == "x" goto execute
-
-set CMD_LINE_ARGS=%*
-
-:execute
-@rem Setup the command line
-
-set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
-
-@rem Execute Gradle
-"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
-
-:end
-@rem End local scope for the variables with windows NT shell
-if "%ERRORLEVEL%"=="0" goto mainEnd
-
-:fail
-rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
-rem the _cmd.exe /c_ return code!
-if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
-exit /b 1
-
-:mainEnd
-if "%OS%"=="Windows_NT" endlocal
-
-:omega
diff --git a/settings.gradle b/settings.gradle
deleted file mode 100644
index 6de09a8c..00000000
--- a/settings.gradle
+++ /dev/null
@@ -1 +0,0 @@
-rootProject.name = "argo-client-java"
\ No newline at end of file