Merge pull request #57 from scala-steward/update/filters-helpers-2.8.18

Update filters-helpers, ... to 2.8.18

Author: mkurz

project/plugins.sbt

@@ -1,5 +1,5 @@
 // The Play plugin
-addSbtPlugin("com.typesafe.play" % "sbt-plugin" % "2.8.17")
+addSbtPlugin("com.typesafe.play" % "sbt-plugin" % "2.8.18")
 
 // Play enhancer - this automatically generates getters/setters for public fields
 // and rewrites accessors of these fields to use the getters/setters. Remove this