Merge pull request scala#214 from SethTisue/scala-2.13

add Scala 2.13 support (drop 2.13.0-RC3)

Author: SethTisue

.travis.yml

@@ -3,7 +3,7 @@ language: scala
 scala:
   - 2.11.12
   - 2.12.8
-  - 2.13.0-RC3
+  - 2.13.0
 jdk:
   - oraclejdk8
   - openjdk11

build.sbt

@@ -45,7 +45,7 @@ lazy val junit = libraryDependencies += "com.novocode" % "junit-interface" % "0.
 
 lazy val scala211 = "2.11.12"
 lazy val scala212 = "2.12.8"
-lazy val scala213 = "2.13.0-RC3"
+lazy val scala213 = "2.13.0"
 
 scalaVersionsByJvm in ThisBuild := {
   val all = List(scala211, scala212, scala213)