Supporting Peer Only configuration for ORA2

@wedaly @ormsbee 

This covers the requirements of TIM-253.  Peer can now be configured for a question without self assessment. 

* Tests updated, still full coverage.
* Loading into devstack to test through there as well. 

@srpearce Please see Line 88 of validation.py  That's the message that'll require updating (I tried my hand at it)