Upgrade branch 2.6.x using TemplateControl (playframework#55)

* Updated with template-control on 2018-09-11T20:14:50.250Z
  **build.sbt:
    scalaVersion := "2.12.6"
  **/plugins.sbt:
    addSbtPlugin("com.typesafe.play" % "sbt-plugin" % "2.6.19")
  **build.gradle:
    def playVersion = "2.6.19"

* Reverse wrong scala replacement

build.gradle

@@ -4,7 +4,7 @@ plugins {
     id "com.github.lkishalmi.gatling" version "0.7.1"
 }
 
-def playVersion = "2.6.18"
+def playVersion = "2.6.19"
 def scalaVersion = System.getProperty("scala.binary.version", /* default = */ "2.12")
 def gatlingVersion = getGlatlingVersion(scalaVersion)
 

project/plugins.sbt

@@ -1,5 +1,5 @@
 // The Play plugin
-addSbtPlugin("com.typesafe.play" % "sbt-plugin" % "2.6.18")
+addSbtPlugin("com.typesafe.play" % "sbt-plugin" % "2.6.19")
 
 // Load testing tool:
 // http://gatling.io/docs/2.2.2/extensions/sbt_plugin.html