Remove last traces of travis integration
PHP 5.4 is now required for master

:beers:
PHP < 5.4 is not supported anymore - see #12606
make \OC\Files\Node\Node implement the FileInfo interface
Merge pull request #12596 from owncloud/remove-travis-traces

Remove last traces of travis integration
Merge pull request #12607 from owncloud/this-is-an-awesome-day

PHP 5.4 is now required for master
Merge pull request #12616 from owncloud/node-fileinfo

make \OC\Files\Node\Node implement the FileInfo interface
Add public api for mount configurations
Use the mount config api for files_external