Add test for showing possible bug where HavaRunner seems to run tests multiple times per scenario.

I would expect it to run test only once per scenario.
Update scala to 2.11.2, sbt to 0.13.2 & guava to 17 to provide java8 compile time compatibility.
Add test cases for verifying that HavaRunner runs tests multiple times when:

- Test is member of suite
- Test has @AfterAll annotation
Cleanup test
Revert source & guava back to original versions


Did not cause problems
Remove @AfterAll, did not cause problem after all
Skip bridge methods when finding test methods.

This prevents Havarunner from running same tests multiple times on java8.

See http://mail.openjdk.java.net/pipermail/jdk8-dev/2014-January/003955.html and
https://bugs.openjdk.java.net/browse/JDK-6695379
Use scala 2.11.2 for travis too
Upgrade junit-interface
Add state to VerifyThatTestAreRunOnlyOnceTestSuperClass to avoid false failures when running via sbt.

When HavaRunner tests are executed via SBT, both VerifyThatTestAreRunOnlyOnceSuiteImpl and VerifyThatTestAreRunOnlyOnceTestOneImpl are executed,
resulting in tests running twice, thus failing the java8 assertions here..

This flag prevents that
Update changelog
Update vcs-release (forced by sbt upgrade)
Add support for publishSigned

http://www.scala-sbt.org/0.13/docs/Using-Sonatype.html
Run against JDK 7 and 8 on Travis
Pump up version
Merge branch 'add-java-8-support'

Conflicts:
	README.md