Unit tests for account/backend.py
Unit tests for account/backend.py

Add test for database create request without account
Partial test for migrate call on database with storage_policy_index

Change-Id: I7cfbd6bc7e2b341f433d88f600b19e54826a0e22
Signed-off-by: Ganesh Maharaj Mahalingam <e84b6eb1374b2034268ad16b797fbec9318eafab@intel.com>

levythu/swift,williamthegrey/swift,psachin/swift,thiagodasilva/swift,tipabu/swift,smerritt/swift,aerwin3/swift,notmyname/swift,openstack/swift,daasbank/swift,larsbutler/swift,clayg/swift,revoer/keystone-8.0.0,redbo/swift,psachin/swift,hurricanerix/swift,tipabu/swift,larsbutler/swift,williamthegrey/swift,aerwin3/swift,matthewoliver/swift,nadeemsyed/swift,tipabu/swift,levythu/swift,nadeemsyed/swift,nadeemsyed/swift,clayg/swift,matthewoliver/swift,revoer/keystone-8.0.0,matthewoliver/swift,clayg/swift,smerritt/swift,smerritt/swift,swiftstack/swift,hurricanerix/swift,openstack/swift,thiagodasilva/swift,psachin/swift,notmyname/swift,tipabu/swift,hurricanerix/swift,nadeemsyed/swift,rackerlabs/swift,openstack/swift,smerritt/swift,prashanthpai/swift,psachin/swift,swiftstack/swift,notmyname/swift,daasbank/swift,redbo/swift,rackerlabs/swift,notmyname/swift,swiftstack/swift,prashanthpai/swift,hurricanerix/swift,clayg/swift,openstack/swift,matthewoliver/swift