Improve List Role Assignment Tests
Improve List Role Assignment Tests

Add new tests to role_assignments API.
Filters + effective mode are combined in order to
cover all allowed and forbidden cases.

Closes-Bug: 1396083

Change-Id: Ia076539b6099bd32ff3f8e3ee6930b7ecb9bbd7b

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