Handle releases on Travis CI via sbt-ci-release

.travis.yml

@@ -1,8 +1,18 @@
 language: scala
 jdk: openjdk8
+git:
+  depth: false
 cache:
   directories:
   - $HOME/.cache
   - $HOME/.ivy2/cache
   - $HOME/.sbt
-script: sbt test
+stages:
+  - name: test
+  - name: release
+    if: (branch = master AND type = push) OR (tag IS present)
+jobs:
+  include:
+  - script: sbt test
+  - stage: release
+    script: sbt ci-release

build.sbt

@@ -22,3 +22,15 @@ crossVersion := CrossVersion.disabled
 // test stuff
 libraryDependencies += "com.novocode" % "junit-interface" % "0.11" % "test"
 fork.in(Test) := true // seems required for the tests to run fine
+
+// sbt-dynver doesn't generate correct versions, because tags don't have a
+// 'v' prefix, so we're overriding its logic here
+version := {
+  import sys.process._
+  val describe = Seq("git", "describe", "--tags").!!.trim
+  val latestTag = Seq("git", "describe", "--tags", "--abbrev=0").!!.trim
+  if (describe == latestTag)
+    describe
+  else
+    describe + "-SNAPSHOT"
+}

project/plugins.sbt

@@ -0,0 +1 @@
+addSbtPlugin("com.geirsson" % "sbt-ci-release" % "1.2.2")