Cleanup oauth tests
Cleanup oauth tests

In a lot of places this code was using dict.get() where [] makes
more sense because the code then assumes that the field was
present and had a value. Using .get() just means that if the code
changes the error would be an unexpected TypeError on a different
line than where the problem actually was.

Also, building of simple url strings was simplified to remove the
dict so that they could be kept on a single line.

Change-Id: I98b5631e02fe1456f0f583c4ec55c9ac0f8c4c35

rodrigods/keystone,dstanek/keystone,dims/keystone,takeshineshiro/keystone,maestro-hybrid-cloud/keystone,cernops/keystone,himanshu-setia/keystone,roopali8/keystone,ilay09/keystone,ging/keystone,vivekdhayaal/keystone,MaheshIBM/keystone,UTSA-ICS/keystone-kerberos,mahak/keystone,maestro-hybrid-cloud/keystone,rajalokan/keystone,nuxeh/keystone,reeshupatel/demo,nuxeh/keystone,promptworks/keystone,dims/keystone,dstanek/keystone,idjaw/keystone,JioCloud/keystone,ajayaa/keystone,idjaw/keystone,reeshupatel/demo,openstack/keystone,takeshineshiro/keystone,mahak/keystone,promptworks/keystone,vivekdhayaal/keystone,himanshu-setia/keystone,nuxeh/keystone,blueboxgroup/keystone,rushiagr/keystone,ilay09/keystone,klmitch/keystone,rajalokan/keystone,ajayaa/keystone,dstanek/keystone,rushiagr/keystone,klmitch/keystone,promptworks/keystone,jumpstarter-io/keystone,rushiagr/keystone,jumpstarter-io/keystone,UTSA-ICS/keystone-kerberos,rajalokan/keystone,jonnary/keystone,reeshupatel/demo,openstack/keystone,roopali8/keystone,blueboxgroup/keystone,MaheshIBM/keystone,jamielennox/keystone,jumpstarter-io/keystone,vivekdhayaal/keystone,mahak/keystone,jamielennox/keystone,jonnary/keystone,ging/keystone,JioCloud/keystone,rodrigods/keystone,cernops/keystone,ilay09/keystone,openstack/keystone