bump scala 2.13 to latest milestone (M5)

Author: jozic

build.sbt

@@ -19,7 +19,7 @@ lazy val commonSettings =
       source.close
       version.get
     },
-    crossScalaVersions := Seq("2.11.12", "2.12.8", "2.13.0-M2"),
+    crossScalaVersions := Seq("2.11.12", "2.12.8", "2.13.0-M5"),
     scalacOptions ++= Seq(
       "-unchecked",
       "-feature",