Fix the Travis builds
Fix the Travis builds

- Nextcloud master branch is no longer compatible with PHP 7.0 => test it
with PHP 7.2
- The Makefile in onwCloud 10.x has changed so that it's not compatible with
our Travis environment. The file is now patched slightly before running
'make'.

Kudos to @Faldon for finding out the causes and fixes within the PR #688.

paulijar/music,paulijar/music,paulijar/music,owncloud/music,owncloud/music,paulijar/music,owncloud/music,owncloud/music,owncloud/music,paulijar/music