Update .travis.yml
SONATA-195 - Added bootstrap3 support
Merge pull request #107 from Bladrak/SONATA-195

SONATA-195 - Added bootstrap3 support
Fixed KnpMenuBundle (now optional dependency)
Merge pull request #108 from Bladrak/fixedKnpMenuDependency

Fixed KnpMenuBundle (now optional dependency)
Merge branch 'sonata/master'

Conflicts:
	composer.json