[TASK] travis-ci: Silence selenium and php server

codeception creates fine output in case something goes wrong,
it looks as if we can throw away selenium and php server output
to console for now to have a better overview in travis again.

Change-Id: Idbc9f257fdbb41a6bb7d12c756cea5c7679852dc
Resolves: #73681
Releases: master
Reviewed-on: https://review.typo3.org/46899


Reviewed-by: Mathias Brodala <mbrodala@pagemachine.de>
Tested-by: Mathias Brodala <mbrodala@pagemachine.de>
Reviewed-by: Frank Naegler <frank.naegler@typo3.org>
Tested-by: Frank Naegler <frank.naegler@typo3.org>