Build: Test against multiple JDKs on Travis
Build: Test against multiple JDKs on Travis

* Use NODE_VERSION instead of TRAVIS_NODE_VERSION
* Install node version before attempting to use it
* Don't need to explicitly use after install
* Don't test against openjdk6
* Print version information for build tools

Ref #62
Closes #64

jzaefferer/grunt-html,wesjones/grunt-html,wesjones/grunt-html,jzaefferer/grunt-html,wesjones/grunt-html,jzaefferer/grunt-html