project/plugins.sbt (4 lines of code) (raw):
resolvers += "spray repo" at "https://repo.spray.io"
addSbtPlugin("io.spray" % "sbt-revolver" % "0.7.2")
addSbtPlugin("io.spray" % "sbt-twirl" % "0.7.0")
addSbtPlugin("com.typesafe.sbt" % "sbt-start-script" % "0.10.0")