Updating travis test specification

As travis builds seem to fail due to using the wrong sbt version, this is something of a hack to make sure they run a sbt version (the one included with piper) that I know work.
Removing building for OpenJDK

The travis build problem only seems to pop up for the OpenJDK, so I'm removing it from the build to see if it helps.
tests as script instead of test
Merge pull request #2 from johandahlberg/master

Release v1.1.1 - "Boomer"

As Travis stuff failed with previous pull request. This is a new one where test script for Travis has been fixed.