Fix a ZeroDivisionError for short replicator runs.
Fix a ZeroDivisionError for short replicator runs.

During unittest runs it's possible for time.time() - self.start
to be zero. This patch sets the elapsed value to an arbitrarily
small number to prevent divide by zero errors.

Change-Id: I20d4b9bf7ff3cdce4e9fe3215622c01cfec7f8bb

Akanoa/swift,redbo/swift,aerwin3/swift,hbhdytf/mac,iostackproject/IO-Bandwidth-Differentiation,citrix-openstack-build/swift,sarvesh-ranjan/swift,smerritt/swift,psachin/swift,nadeemsyed/swift,nadeemsyed/swift,iostackproject/IO-Bandwidth-Differentiation,psachin/swift,daasbank/swift,Triv90/SwiftUml,williamthegrey/swift,NewpTone/StackLab-swift,psachin/swift,maginatics/swift,Mirantis/swift-encrypt,hbhdytf/mac2,clayg/swift,redhat-openstack/swift,notmyname/swift,Akanoa/swift,Seagate/swift,dpgoetz/swift,wenhuizhang/swift,Em-Pan/swift,aerwin3/swift,citrix-openstack/build-swift,thiagodasilva/swift,dpgoetz/swift,notmyname/swift,revoer/keystone-8.0.0,redbo/swift,dencaval/swift,hbhdytf/mac2,bkolli/swift,zaitcev/swift-lfs,VictorLowther/swift,notmyname/swift,tsli/test,wenhuizhang/swift,JioCloud/swift,mjzmjz/swift,citrix-openstack-build/swift,scality/ScalitySproxydSwift,orion/swift-config,shibaniahegde/OpenStak_swift,takeshineshiro/swift,clayg/swift,matthewoliver/swift,daasbank/swift,mjwtom/swift,Khushbu27/Tutorial,hurricanerix/swift,tipabu/swift,JioCloud/swift,hbhdytf/mac2,sarvesh-ranjan/swift,bkolli/swift,AfonsoFGarcia/swift,eatbyte/Swift,xiaoguoai/ec-dev-swift,tipabu/swift,rackerlabs/swift,takeshineshiro/swift,dencaval/swift,matthewoliver/swift,openstack/swift,rackerlabs/swift,anishnarang/gswift,williamthegrey/swift,bradleypj823/swift,Triv90/SwiftUml,xiaoguoai/ec-dev-swift,scality/ScalitySproxydSwift,maginatics/swift,hbhdytf/mac,IPVL/swift-kilo,nadeemsyed/swift,redhat-openstack/swift,zaitcev/swift-lfs,zackmdavis/swift,psachin/swift,bouncestorage/swift,clayg/swift,Khushbu27/Tutorial,openstack/swift,thiagodasilva/swift,mjwtom/swift,bouncestorage/swift,anishnarang/gswift,clayg/swift,NeCTAR-RC/swift,matthewoliver/swift,smerritt/swift,NeCTAR-RC/swift,AfonsoFGarcia/swift,hurricanerix/swift,tipabu/swift,hurricanerix/swift,smerritt/swift,openstack/swift,levythu/swift,notmyname/swift,prashanthpai/swift,swiftstack/swift,Mirantis/swift-encrypt,hurricanerix/swift,IPVL/swift-kilo,prashanthpai/swift,revoer/keystone-8.0.0,mjzmjz/swift,swiftstack/swift,Em-Pan/swift,openstack/swift,bradleypj823/swift,zackmdavis/swift,swiftstack/swift,Seagate/swift,gold3bear/swift,citrix-openstack/build-swift,larsbutler/swift,matthewoliver/swift,orion/swift-config,tipabu/swift,nadeemsyed/swift,smerritt/swift,levythu/swift,shibaniahegde/OpenStak_swift,larsbutler/swift,NewpTone/StackLab-swift,hbhdytf/mac2,VictorLowther/swift,eatbyte/Swift,tsli/test,gold3bear/swift