add unit tests for db_replicator
add unit tests for db_replicator

Change-Id: I9002fa193a51f40523e7936e3117a2f3f2b2f7f8

clayg/swift,nadeemsyed/swift,JioCloud/swift,tsli/test,notmyname/swift,nadeemsyed/swift,Em-Pan/swift,Khushbu27/Tutorial,citrix-openstack/build-swift,tipabu/swift,williamthegrey/swift,zaitcev/swift-lfs,mjzmjz/swift,matthewoliver/swift,aerwin3/swift,hurricanerix/swift,prashanthpai/swift,bouncestorage/swift,clayg/swift,Khushbu27/Tutorial,smerritt/swift,nadeemsyed/swift,bkolli/swift,levythu/swift,tipabu/swift,redhat-openstack/swift,gold3bear/swift,shibaniahegde/OpenStak_swift,zackmdavis/swift,matthewoliver/swift,takeshineshiro/swift,larsbutler/swift,orion/swift-config,hbhdytf/mac,redhat-openstack/swift,dencaval/swift,hbhdytf/mac2,aerwin3/swift,redbo/swift,maginatics/swift,notmyname/swift,smerritt/swift,hurricanerix/swift,smerritt/swift,swiftstack/swift,psachin/swift,larsbutler/swift,rackerlabs/swift,swiftstack/swift,daasbank/swift,bradleypj823/swift,notmyname/swift,revoer/keystone-8.0.0,scality/ScalitySproxydSwift,dencaval/swift,NeCTAR-RC/swift,rackerlabs/swift,clayg/swift,iostackproject/IO-Bandwidth-Differentiation,nadeemsyed/swift,takeshineshiro/swift,NeCTAR-RC/swift,revoer/keystone-8.0.0,anishnarang/gswift,wenhuizhang/swift,psachin/swift,tipabu/swift,zackmdavis/swift,mjwtom/swift,anishnarang/gswift,gold3bear/swift,thiagodasilva/swift,bkolli/swift,psachin/swift,hurricanerix/swift,openstack/swift,Em-Pan/swift,hbhdytf/mac2,Akanoa/swift,zaitcev/swift-lfs,iostackproject/IO-Bandwidth-Differentiation,maginatics/swift,Akanoa/swift,williamthegrey/swift,eatbyte/Swift,Seagate/swift,IPVL/swift-kilo,hurricanerix/swift,openstack/swift,mjzmjz/swift,sarvesh-ranjan/swift,matthewoliver/swift,levythu/swift,dpgoetz/swift,hbhdytf/mac,citrix-openstack-build/swift,AfonsoFGarcia/swift,IPVL/swift-kilo,scality/ScalitySproxydSwift,openstack/swift,Seagate/swift,matthewoliver/swift,shibaniahegde/OpenStak_swift,sarvesh-ranjan/swift,clayg/swift,daasbank/swift,citrix-openstack-build/swift,tipabu/swift,bouncestorage/swift,mjwtom/swift,psachin/swift,thiagodasilva/swift,hbhdytf/mac2,wenhuizhang/swift,openstack/swift,prashanthpai/swift,orion/swift-config,AfonsoFGarcia/swift,citrix-openstack/build-swift,tsli/test,notmyname/swift,eatbyte/Swift,redbo/swift,swiftstack/swift,bradleypj823/swift,dpgoetz/swift,hbhdytf/mac2,xiaoguoai/ec-dev-swift,JioCloud/swift,smerritt/swift,xiaoguoai/ec-dev-swift