Revert "center quotation text"

This reverts commit 8a8991ba87967dd4f7ddcc437a18c4f09ae94cb1.

Conflicts:
	src/plugins/oer/quotation/css/quotation-plugin.css
Merge branch 'feature/quotation' into testing
Merge branch 'testing' of github.com:oerpub/Aloha-Editor into testing