Feature dependency definition in build.gradle (#41)

Description
===========

This is the first part if bringing the basic paket configuration
(paket.dependencies, paket.template, paket.references) into the gradle
project. This change adds custom `paket` dependency handler to the
gradle dependency handler and a nuget repository factory.

*build.gradle*
```groovy
dependencies {
    paket {
        nuget "Test ~> 1"
    }
}

repositories {
   nuget {
       url 'some/url'
   }
}
```

At the moment only `nuget` dependencies are supported.
When dependencies are configured in the `build.gradle` file, a
`paket.dependencies` file will be generated. If this file already
exists, it will be overridden.

Changes
=======

![ADD] paket dependencies handler
![ADD] nuget dependency definition
![ADD] nuget dependency source artifact repository handler
![ADD] new task `paketDependencies`

build.gradle

@@ -68,4 +68,6 @@ dependencies {
     testCompile('org.jfrog.artifactory.client:artifactory-java-client-services:2.+') {
         exclude module: 'logback-classic'
     }
+
+    compile('com.google.guava:guava:19.0')
 }

src/integrationTest/groovy/wooga/gradle/paket/IntegrationSpec.groovy

@@ -18,13 +18,26 @@
 package wooga.gradle.paket
 
 import org.apache.commons.io.FileUtils
+import org.apache.commons.lang.StringEscapeUtils
 import spock.lang.Shared
 
 class IntegrationSpec extends nebula.test.IntegrationSpec{
 
     @Shared
     File cachedPaketDir
 
+    def escapedPath(String path) {
+        String osName = System.getProperty("os.name").toLowerCase()
+        if (osName.contains("windows")) {
+            return StringEscapeUtils.escapeJava(path)
+        }
+        path
+    }
+
+    def convertToWindowsPath(String path) {
+        new File(path).toString()
+    }
+
     def setupSpec() {
         cachedPaketDir = File.createTempDir("paket","cache")
         cachedPaketDir.deleteOnExit()

src/integrationTest/groovy/wooga/gradle/paket/PaketIntegrationBaseSpec.groovy

@@ -20,6 +20,7 @@ package wooga.gradle.paket
 import nebula.test.functional.ExecutionResult
 import spock.lang.Shared
 import spock.lang.Unroll
+import wooga.gradle.paket.base.PaketBasePlugin
 
 abstract class PaketIntegrationBaseSpec extends IntegrationSpec {
 
@@ -58,6 +59,18 @@ abstract class PaketIntegrationBaseSpec extends IntegrationSpec {
         taskToRun << bootstrapTestCases
     }
 
+    @Unroll
+    def "task :paketBootstrap calls :paketDependencies when runing #taskToRun"(String taskToRun) {
+        when:
+        def result = runTasksSuccessfully(taskToRun)
+
+        then:
+        result.wasExecuted(PaketBasePlugin.PAKET_DEPENDENCIES_TASK_NAME)
+
+        where:
+        taskToRun << bootstrapTestCases
+    }
+
     @Unroll
     def "skip bootstrap when files are [UP-TO-DATE] when running #taskToRun"(String taskToRun) {
         given: "a paket dependency file"

src/integrationTest/groovy/wooga/gradle/paket/PaketIntegrationDependencyFileSpec.groovy

@@ -155,7 +155,5 @@ abstract class PaketIntegrationDependencyFileSpec extends PaketIntegrationBaseSp
         then: "evaluate incremental task execution"
         result.wasExecuted("paketInstall")
         result.wasExecuted(PaketUnityPlugin.INSTALL_TASK_NAME)
-
-
     }
 }