[TASK] travis: Acceptance tests with nginx+fpm

* Start a php-fpm server on port 9000
* Install nginx, configure and start on port 8000 for acceptance tests
* Use phantomjs provided by composer directly without selenium

Change-Id: Ie25c27d765437ed0a12d1df9b0c9b1a4355b1024
Resolves: #75837
Releases: master
Reviewed-on: https://review.typo3.org/47815


Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>