Manage Scala versions in one place.

.travis.yml

@@ -2,7 +2,7 @@ dist: xenial
 language: scala
 
 scala:
-  - 2.12.8
+  - 2.12.9
   - 2.13.0
 
 env:

build.sbt

@@ -1,10 +1,6 @@
 import sbt.url
 import sbtrelease.ReleaseStateTransformations._
 
-val scala212Version       = "2.12.8"
-val scala213Version       = "2.13.0"
-val supportedScalaVersion = Seq(scala212Version, scala213Version)
-
 val scalatestVersion = "3.0.8"
 val scalacticVersion = "3.0.8"
 val enableIfVersion  = "1.1.7"
@@ -13,7 +9,6 @@ organization in ThisBuild := "net.exoego"
 
 lazy val commonSettings = Seq(
   autoCompilerPlugins := true,
-  crossScalaVersions := supportedScalaVersion,
   scalacOptions ++= Seq(
     "-deprecation",
     "-unchecked",

project/plugins.sbt

@@ -4,3 +4,4 @@ addSbtPlugin("org.xerial.sbt"    % "sbt-sonatype"  % "2.5")
 addSbtPlugin("com.github.gseitz" % "sbt-release"   % "1.0.11")
 addSbtPlugin("com.jsuereth"      % "sbt-pgp"       % "1.1.2")
 addSbtPlugin("org.scoverage"     % "sbt-scoverage" % "1.6.0")
+addSbtPlugin("com.dwijnand"      % "sbt-travisci"  % "1.2.0")