Bump versions

https://www.playframework.com/changelog

https://groups.google.com/forum/#!topic/play-framework/yWIeCry1kGc

Author: rtyley

project/build.properties

@@ -1 +1 @@
-sbt.version=0.13.9-RC3
+sbt.version=0.13.9

project/plugins.sbt

@@ -4,6 +4,6 @@ logLevel := Level.Warn
 resolvers += Resolver.typesafeRepo("releases") // Play seems to require quite a few things from here
 
 // Use the Play sbt plugin for Play projects
-addSbtPlugin("com.typesafe.play" % "sbt-plugin" % "2.4.2")
+addSbtPlugin("com.typesafe.play" % "sbt-plugin" % "2.4.3")
 
 addSbtPlugin("com.eed3si9n" % "sbt-buildinfo" % "0.4.0")