Raise libraries to java 7 level and fix travis-ci build

Reviewing poms for libraries to upgrade with following results.

• Groovy-all from 1.7.6 to 2.4.17
• Slf4j-simple from 1.7.25 to 1.7.30
• Junit from 4.12 to 4.13
• Plexus-utils from 3.1.0 to 3.3.0

Further discovered some trailing spacing and excessive breaking around plugin execution filters.

In order to confirm this worked on the build, I enabled travis-ci on my fork.  I noted a number of problems there.  In order to limit changes, I put it onto 'precise' and removed openjdk6 (project is on 7 currently).