Add snyk dependency graph plugin

To ensure Snyk CLI and dashboard is accurate. See here: https://support.snyk.io/hc/en-us/articles/360004167317-How-to-install-the-SBT-dependency-graph-plugin-to-test-Scala-projects-with-Snyk-CLI

project/plugins.sbt

@@ -5,5 +5,6 @@ addSbtPlugin("com.eed3si9n" % "sbt-buildinfo" % "0.9.0")
 addSbtPlugin("com.typesafe.sbt" % "sbt-less" % "1.1.2")
 addSbtPlugin("org.scalameta" % "sbt-scalafmt" % "2.4.0") // "2.4.0" is just sbt plugin version
 addSbtPlugin("org.scalikejdbc" %% "scalikejdbc-mapper-generator" % "3.5.0")
+addSbtPlugin("net.virtual-void" % "sbt-dependency-graph" % "0.10.0-RC1")
 
 libraryDependencies ++= Seq("org.vafer" % "jdeb" % "1.7" artifacts Artifact("jdeb", "jar", "jar"), "org.postgresql" % "postgresql" % "42.5.1")