Removes xrange for Python3 compat
Removes xrange for Python3 compat

I'm using the builtin range instead of six.moves.range because we're
creating small lists of integers so there really isn't much or a
performance impact.

Change-Id: I9f4a5e9f21e0fd95ffe391eda3aa635938170504
Implements: bp keystone-py3kcompat

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