EndpointFilter driver doesnt inherit its interface
EndpointFilter driver doesnt inherit its interface

Added 'endpoint_filter.Driver' as super class of the sql driver implementation

Change-Id: I1966d89a5f9b3c4c5ef5d9ad6709fc06cbe0c1f7
Closes-Bug: #1485116

openstack/keystone,rajalokan/keystone,idjaw/keystone,roopali8/keystone,dims/keystone,ilay09/keystone,klmitch/keystone,takeshineshiro/keystone,rajalokan/keystone,openstack/keystone,maestro-hybrid-cloud/keystone,mahak/keystone,ajayaa/keystone,jonnary/keystone,dims/keystone,maestro-hybrid-cloud/keystone,idjaw/keystone,jamielennox/keystone,ilay09/keystone,cernops/keystone,openstack/keystone,cernops/keystone,rajalokan/keystone,mahak/keystone,himanshu-setia/keystone,jamielennox/keystone,himanshu-setia/keystone,roopali8/keystone,takeshineshiro/keystone,mahak/keystone,klmitch/keystone,jonnary/keystone,ilay09/keystone,ajayaa/keystone