project/plugins.sbt (4 lines of code) (raw):
// Use the Play sbt plugin for Play projects
addSbtPlugin("org.playframework" % "sbt-plugin" % "3.0.6")
addSbtPlugin("com.github.sbt" % "sbt-release" % "1.4.0")
addSbtPlugin("org.xerial.sbt" % "sbt-sonatype" % "3.11.3")
addSbtPlugin("ch.epfl.scala" % "sbt-version-policy" % "3.2.1")