[TASK] Execute Extbase and Fluid tests on travis

Until now no tests from system extensions are executed
on travis ci.

Add a phpunit configuration file and add Extbase and Fluid
tests as test suites. Be aware that travis currently uses
the current submodule pointer and does not check out master
of submodules.

Resolves: #39954
Releases: 6.0
Change-Id: I949a65b0f1628fdfa4515e3fb4536517430dccac
Reviewed-on: http://review.typo3.org/13912
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn