Removed romanian translation for 2.0, too

Refs https://github.com/cakephp/docs/pull/1948

The Romanian translation was started but not kept up to date for quite some time now:

The commits in this tree are not many:
https://github.com/cakephp/docs/commits/master/ro
Merge pull request #1950 from cakephp/2.0-romanian-removal

Removed romanian translation for 2.0, too