versioning by tagging + release documentation (#44)

dynamic versioning using sbt-dynver plugin
release documentation
update sbt-sonatype plugin

Author: kwark

project/plugins.sbt

@@ -3,10 +3,8 @@ logLevel := Level.Warn
 addSbtPlugin("io.gatling" % "gatling-sbt" % "2.2.2")
 
 // supports release in maven central
-
-addSbtPlugin("org.xerial.sbt" % "sbt-sonatype" % "2.3")
-
+addSbtPlugin("org.xerial.sbt" % "sbt-sonatype" % "2.5")
 addSbtPlugin("com.jsuereth" % "sbt-pgp" % "1.1.2")
-
 addSbtPlugin("com.dwijnand" % "sbt-travisci" % "1.1.3")
+addSbtPlugin("com.dwijnand" % "sbt-dynver" % "3.3.0")
 

release.md

@@ -0,0 +1,14 @@
+# Release Procedure
+
+Artefacts are published to [Sonatype OSS](https://oss.sonatype.org/), 
+which sync's with Maven Central repositories.
+
+The following procedure is executed manually:
+
+~~~
+$ sbt +test # tests the code
+$ git tag -vX.Y.Z -m "release version X.Y.Z"  
+$ sbt +publishSigned  #publishes the signed artefacts to staging
+$ sbt sonatypeRelease
+$ git push --tags origin develop
+~~~