add Scala 2.13.6 to crossbuild

Author: SethTisue

.travis.yml

@@ -87,6 +87,10 @@ env:
     TRAVIS_JDK=adopt@~1.8.0-0
   - SCALA_VERSION=2.13.5
     TRAVIS_JDK=adopt@~1.11.0-0
+  - SCALA_VERSION=2.13.6
+    TRAVIS_JDK=adopt@~1.8.0-0
+  - SCALA_VERSION=2.13.6
+    TRAVIS_JDK=adopt@~1.11.0-0
 
 before_install: curl -Ls https://git.io/jabba | bash && . ~/.jabba/jabba.sh
 install: jabba install "$TRAVIS_JDK" && jabba use "$_" && java -Xmx32m -version

build.sbt

@@ -51,7 +51,7 @@ lazy val defaults = Seq(
     val supportedScala211Versions = Seq("2.11.6", "2.11.7", "2.11.8", "2.11.11", "2.11.12")
     // Scala 2.12.[0-2] are not supported
     val supportedScala212Versions = (3 to 13).map(p => s"2.12.$p")
-    val supportedScala213Versions = (0 to 5).map(p => s"2.13.$p")
+    val supportedScala213Versions = (0 to 6).map(p => s"2.13.$p")
     supportedScala211Versions ++ supportedScala212Versions ++ supportedScala213Versions
   },
   scalaMajorVersion := CrossVersion.partialVersion(scalaVersion.value).get._2.toInt,