Add testing of Ruby 2.1.0/2.1.1 in Travis

We temporarily disable Ruby 2.1.0 however, due to:

    https://github.com/travis-ci/travis-ci/issues/2220

Change-Id: If7c1a5da5f5dbd8ec926fd7f772e145c99828be6
Reviewed-on: http://gerrit.causes.com/37739
Reviewed-by: Shane da Silva <shane@causes.com>
Tested-by: Shane da Silva <shane@causes.com>