[TASK] Run the unit tests on TravisCI

The github repository will be find at https://github.com/typo3-ci/ext-phpunit and the Travis jobs at https://travis-ci.org/typo3-ci/ext-phpunit

Fixes: 49741
Change-Id: I7c76ede923ffee202a55d5a4a08d0f6c6e76bd40