Upgrade to Scala 2.13

Author: olafurpg

build.sbt

@@ -4,7 +4,7 @@ import OsgiKeys._
 val scala210 = "2.10.7"
 val scala211 = "2.11.12"
 val scala212 = "2.12.8"
-val scala213 = "2.13.0-M5"
+val scala213 = "2.13.0-RC1"
 
 inThisBuild(List(
   organization := "com.lihaoyi",

project/build.sbt

@@ -1,6 +1,6 @@
 
 val scalaJSVersion =
-  Option(System.getenv("SCALAJS_VERSION")).getOrElse("0.6.25")
+  Option(System.getenv("SCALAJS_VERSION")).getOrElse("0.6.27")
 
 addSbtPlugin("org.scala-js" % "sbt-scalajs" % scalaJSVersion)