use edxapp instead of individual gunicorn processes
Merge remote-tracking branch 'origin/master' into fix/jbau/edxapp_instead_of_lms_cms_in_production

Conflicts:
	playbooks/edx-west/edxapp_prod.yml
missed some conversions of adding edx_ prefix to platform_code_dirs
Merge pull request #123 from edx/fix/jbau/edxapp_instead_of_lms_cms_in_production

use edxapp instead of individual gunicorn processes