Add missing tests for s3_image_* methods
Add missing tests for s3_image_* methods

There was no tests in test_db_api for s3_image_*
methods.

Add tests to ensure that all works.

blueprint db-api-tests

Change-Id: I906025f4c5178b26c222fb28d5c3b220e00ae79c

cloudbase/nova,ruslanloman/nova,mmnelemane/nova,nikesh-mahalka/nova,mahak/nova,eharney/nova,phenoxim/nova,hanlind/nova,apporc/nova,ted-gould/nova,barnsnake351/nova,double12gzh/nova,mmnelemane/nova,cernops/nova,sacharya/nova,mandeepdhami/nova,berrange/nova,leilihh/novaha,rahulunair/nova,BeyondTheClouds/nova,mahak/nova,alexandrucoman/vbox-nova-driver,SUSE-Cloud/nova,jeffrey4l/nova,tealover/nova,BeyondTheClouds/nova,maelnor/nova,redhat-openstack/nova,felixma/nova,ntt-sic/nova,alexandrucoman/vbox-nova-driver,Stavitsky/nova,eayunstack/nova,zzicewind/nova,scripnichenko/nova,NeCTAR-RC/nova,CCI-MOC/nova,Metaswitch/calico-nova,viggates/nova,devendermishrajio/nova,Juniper/nova,iuliat/nova,apporc/nova,BeyondTheClouds/nova,blueboxgroup/nova,petrutlucian94/nova_dev,isyippee/nova,rrader/nova-docker-plugin,leilihh/novaha,akash1808/nova,raildo/nova,jianghuaw/nova,bclau/nova,bigswitch/nova,yatinkumbhare/openstack-nova,tianweizhang/nova,openstack/nova,qwefi/nova,j-carpentier/nova,silenceli/nova,luogangyi/bcec-nova,takeshineshiro/nova,spring-week-topos/nova-week,rajalokan/nova,zhimin711/nova,orbitfp7/nova,openstack/nova,jianghuaw/nova,devendermishrajio/nova,tudorvio/nova,tanglei528/nova,klmitch/nova,DirectXMan12/nova-hacking,scripnichenko/nova,blueboxgroup/nova,shail2810/nova,TieWei/nova,mikalstill/nova,fnordahl/nova,akash1808/nova_test_latest,whitepages/nova,tangfeixiong/nova,dims/nova,double12gzh/nova,citrix-openstack-build/nova,silenceli/nova,eonpatapon/nova,alaski/nova,jianghuaw/nova,JioCloud/nova,mandeepdhami/nova,yosshy/nova,klmitch/nova,OpenAcademy-OpenStack/nova-scheduler,watonyweng/nova,jianghuaw/nova,JioCloud/nova,adelina-t/nova,cernops/nova,plumgrid/plumgrid-nova,gooddata/openstack-nova,varunarya10/nova_test_latest,TwinkleChawla/nova,rickerc/nova_audit,affo/nova,mgagne/nova,leilihh/nova,petrutlucian94/nova,JianyuWang/nova,rahulunair/nova,Juniper/nova,rickerc/nova_audit,alvarolopez/nova,kimjaejoong/nova,noironetworks/nova,akash1808/nova_test_latest,rajalokan/nova,sebrandon1/nova,qwefi/nova,akash1808/nova,cyx1231st/nova,projectcalico/calico-nova,fnordahl/nova,virtualopensystems/nova,JianyuWang/nova,dawnpower/nova,tealover/nova,CCI-MOC/nova,Francis-Liu/animated-broccoli,yosshy/nova,dawnpower/nova,CEG-FYP-OpenStack/scheduler,ewindisch/nova,Yuriy-Leonov/nova,orbitfp7/nova,iuliat/nova,devoid/nova,sacharya/nova,joker946/nova,SUSE-Cloud/nova,Stavitsky/nova,gooddata/openstack-nova,sebrandon1/nova,ted-gould/nova,LoHChina/nova,barnsnake351/nova,cloudbase/nova-virtualbox,viggates/nova,nikesh-mahalka/nova,berrange/nova,thomasem/nova,NeCTAR-RC/nova,shahar-stratoscale/nova,luogangyi/bcec-nova,tudorvio/nova,takeshineshiro/nova,varunarya10/nova_test_latest,ntt-sic/nova,alvarolopez/nova,felixma/nova,bclau/nova,hanlind/nova,mahak/nova,Yusuke1987/openstack_template,kimjaejoong/nova,leilihh/nova,vmturbo/nova,eonpatapon/nova,vladikr/nova_drafts,spring-week-topos/nova-week,angdraug/nova,edulramirez/nova,devendermishrajio/nova_test_latest,edulramirez/nova,raildo/nova,DirectXMan12/nova-hacking,hanlind/nova,mgagne/nova,eayunstack/nova,openstack/nova,adelina-t/nova,petrutlucian94/nova,mikalstill/nova,plumgrid/plumgrid-nova,cloudbase/nova,TwinkleChawla/nova,shail2810/nova,petrutlucian94/nova_dev,vmturbo/nova,bgxavier/nova,whitepages/nova,ruslanloman/nova,devendermishrajio/nova_test_latest,zzicewind/nova,tanglei528/nova,watonyweng/nova,phenoxim/nova,Metaswitch/calico-nova,bgxavier/nova,Tehsmash/nova,klmitch/nova,projectcalico/calico-nova,Brocade-OpenSource/OpenStack-DNRM-Nova,TieWei/nova,dims/nova,belmiromoreira/nova,cloudbau/nova,Juniper/nova,badock/nova,rajalokan/nova,bigswitch/nova,cloudbase/nova,jeffrey4l/nova,joker946/nova,JioCloud/nova_test_latest,sebrandon1/nova,maelnor/nova,imsplitbit/nova,saleemjaveds/https-github.com-openstack-nova,shootstar/novatest,zaina/nova,shahar-stratoscale/nova,cloudbau/nova,rrader/nova-docker-plugin,tianweizhang/nova,Brocade-OpenSource/OpenStack-DNRM-Nova,mikalstill/nova,angdraug/nova,Yusuke1987/openstack_template,vmturbo/nova,CiscoSystems/nova,cernops/nova,Tehsmash/nova,CiscoSystems/nova,rajalokan/nova,imsplitbit/nova,shootstar/novatest,belmiromoreira/nova,j-carpentier/nova,badock/nova,CloudServer/nova,klmitch/nova,OpenAcademy-OpenStack/nova-scheduler,isyippee/nova,alaski/nova,gooddata/openstack-nova,zhimin711/nova,yatinkumbhare/openstack-nova,vmturbo/nova,JioCloud/nova_test_latest,devoid/nova,DirectXMan12/nova-hacking,saleemjaveds/https-github.com-openstack-nova,CEG-FYP-OpenStack/scheduler,eharney/nova,Yuriy-Leonov/nova,zaina/nova,noironetworks/nova,tangfeixiong/nova,virtualopensystems/nova,MountainWei/nova,gooddata/openstack-nova,cyx1231st/nova,vladikr/nova_drafts,Francis-Liu/animated-broccoli,thomasem/nova,Juniper/nova,CloudServer/nova,citrix-openstack-build/nova,MountainWei/nova,redhat-openstack/nova,cloudbase/nova-virtualbox,affo/nova,ewindisch/nova,LoHChina/nova,rahulunair/nova