Fix 500 when min_review_count is 0 and get_submission_and_review_steps() returns None. 	Change on 2014/09/02 by johncox <johncox@google.com> ------------- Created by MOE: http://code.google.com/p/moe-java MOE_MIGRATED_REVID=74656041
Fix 500 when min_review_count is 0 and get_submission_and_review_steps() returns None.
	Change on 2014/09/02 by johncox <johncox@google.com>
-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=74656041

andela-angene/coursebuilder-core,andela-angene/coursebuilder-core,andela-angene/coursebuilder-core,andela-angene/coursebuilder-core