First pass at implementing the keystone auth backend
First pass at implementing the keystone auth backend

Manual testing suggests this is working; need to add some automated
tests.

meng-sun/hil,henn/hil_sahil,kylehogan/hil,meng-sun/hil,CCI-MOC/haas,kylehogan/hil,henn/haas,henn/hil,henn/hil,SahilTikale/haas,kylehogan/haas,henn/hil_sahil