Hacking cache generation for heroku

[hack] Hacking jms serialization for heroku
[hack] Hacking symfony cache due to https://github.com/symfony/symfony/issues/12893 / see https://github.com/symfony/symfony/pull/12784
Merge branch 'master' of ssh://stash.fansworld.tv:7999/~dc/heroku-buildpack-php

Conflicts:
	bin/compile
	bin/fix-metadata-paths
[hack] Force serialization