improve sessions for reservation
improve sessions for reservation

improve session handling for
  reservation_(get|destroy)

blueprint db-session-cleanup

Change-Id: I1b6e9a903ef8c3df7449201a2103dc720cdf0e31

barnsnake351/nova,alvarolopez/nova,devendermishrajio/nova_test_latest,tanglei528/nova,belmiromoreira/nova,double12gzh/nova,TieWei/nova,mahak/nova,Metaswitch/calico-nova,Yusuke1987/openstack_template,jianghuaw/nova,shahar-stratoscale/nova,cernops/nova,petrutlucian94/nova,devendermishrajio/nova,cloudbase/nova-virtualbox,isyippee/nova,cloudbase/nova,mahak/nova,redhat-openstack/nova,leilihh/nova,sridevikoushik31/openstack,felixma/nova,akash1808/nova_test_latest,JioCloud/nova_test_latest,imsplitbit/nova,mandeepdhami/nova,sridevikoushik31/nova,CiscoSystems/nova,maoy/zknova,gspilio/nova,hanlind/nova,mikalstill/nova,OpenAcademy-OpenStack/nova-scheduler,bclau/nova,barnsnake351/nova,vmturbo/nova,tangfeixiong/nova,phenoxim/nova,bgxavier/nova,fnordahl/nova,alaski/nova,joker946/nova,TwinkleChawla/nova,vmturbo/nova,aristanetworks/arista-ovs-nova,thomasem/nova,jeffrey4l/nova,TwinkleChawla/nova,rrader/nova-docker-plugin,jeffrey4l/nova,tealover/nova,angdraug/nova,zzicewind/nova,belmiromoreira/nova,viggates/nova,zaina/nova,eharney/nova,CiscoSystems/nova,alexandrucoman/vbox-nova-driver,silenceli/nova,cloudbase/nova,sridevikoushik31/openstack,fajoy/nova,yatinkumbhare/openstack-nova,qwefi/nova,CEG-FYP-OpenStack/scheduler,rahulunair/nova,takeshineshiro/nova,kimjaejoong/nova,rajalokan/nova,citrix-openstack-build/nova,zhimin711/nova,apporc/nova,dstroppa/openstack-smartos-nova-grizzly,ruslanloman/nova,Yuriy-Leonov/nova,sridevikoushik31/nova,tudorvio/nova,jianghuaw/nova,spring-week-topos/nova-week,mikalstill/nova,Triv90/Nova,shail2810/nova,petrutlucian94/nova_dev,viggates/nova,fajoy/nova,berrange/nova,petrutlucian94/nova,LoHChina/nova,DirectXMan12/nova-hacking,qwefi/nova,SUSE-Cloud/nova,virtualopensystems/nova,rickerc/nova_audit,devoid/nova,eonpatapon/nova,houshengbo/nova_vmware_compute_driver,rajalokan/nova,affo/nova,silenceli/nova,sebrandon1/nova,shail2810/nova,gspilio/nova,bigswitch/nova,cyx1231st/nova,sebrandon1/nova,j-carpentier/nova,sebrandon1/nova,mgagne/nova,CCI-MOC/nova,MountainWei/nova,mikalstill/nova,dstroppa/openstack-smartos-nova-grizzly,iuliat/nova,orbitfp7/nova,iuliat/nova,vladikr/nova_drafts,tangfeixiong/nova,yatinkumbhare/openstack-nova,thomasem/nova,DirectXMan12/nova-hacking,leilihh/novaha,takeshineshiro/nova,phenoxim/nova,maoy/zknova,zaina/nova,gooddata/openstack-nova,varunarya10/nova_test_latest,eayunstack/nova,CloudServer/nova,houshengbo/nova_vmware_compute_driver,yrobla/nova,adelina-t/nova,bigswitch/nova,saleemjaveds/https-github.com-openstack-nova,Stavitsky/nova,shahar-stratoscale/nova,akash1808/nova,BeyondTheClouds/nova,LoHChina/nova,JioCloud/nova,klmitch/nova,ntt-sic/nova,klmitch/nova,leilihh/novaha,blueboxgroup/nova,adelina-t/nova,raildo/nova,bclau/nova,vmturbo/nova,ewindisch/nova,shootstar/novatest,sridevikoushik31/openstack,rahulunair/nova,devoid/nova,zhimin711/nova,aristanetworks/arista-ovs-nova,berrange/nova,Juniper/nova,scripnichenko/nova,spring-week-topos/nova-week,plumgrid/plumgrid-nova,gooddata/openstack-nova,maheshp/novatest,Stavitsky/nova,Tehsmash/nova,ted-gould/nova,Brocade-OpenSource/OpenStack-DNRM-Nova,noironetworks/nova,shootstar/novatest,watonyweng/nova,raildo/nova,noironetworks/nova,jianghuaw/nova,luogangyi/bcec-nova,sacharya/nova,tealover/nova,ted-gould/nova,blueboxgroup/nova,cernops/nova,CEG-FYP-OpenStack/scheduler,tanglei528/nova,varunarya10/nova_test_latest,yrobla/nova,rrader/nova-docker-plugin,eonpatapon/nova,joker946/nova,ewindisch/nova,fnordahl/nova,cloudbase/nova,whitepages/nova,Francis-Liu/animated-broccoli,NeCTAR-RC/nova,ntt-sic/nova,affo/nova,Juniper/nova,ruslanloman/nova,angdraug/nova,sridevikoushik31/nova,Brocade-OpenSource/OpenStack-DNRM-Nova,cernops/nova,BeyondTheClouds/nova,rajalokan/nova,aristanetworks/arista-ovs-nova,edulramirez/nova,DirectXMan12/nova-hacking,hanlind/nova,mmnelemane/nova,openstack/nova,projectcalico/calico-nova,edulramirez/nova,plumgrid/plumgrid-nova,eayunstack/nova,cloudbau/nova,Francis-Liu/animated-broccoli,fajoy/nova,vladikr/nova_drafts,BeyondTheClouds/nova,cloudbau/nova,houshengbo/nova_vmware_compute_driver,JioCloud/nova,leilihh/nova,badock/nova,nikesh-mahalka/nova,maheshp/novatest,saleemjaveds/https-github.com-openstack-nova,rajalokan/nova,openstack/nova,badock/nova,dawnpower/nova,CCI-MOC/nova,cyx1231st/nova,imsplitbit/nova,klmitch/nova,maoy/zknova,double12gzh/nova,JianyuWang/nova,citrix-openstack-build/nova,zzicewind/nova,mahak/nova,TieWei/nova,petrutlucian94/nova_dev,alvarolopez/nova,kimjaejoong/nova,dstroppa/openstack-smartos-nova-grizzly,watonyweng/nova,virtualopensystems/nova,gspilio/nova,Yusuke1987/openstack_template,maheshp/novatest,luogangyi/bcec-nova,openstack/nova,JioCloud/nova_test_latest,dawnpower/nova,eharney/nova,gooddata/openstack-nova,dims/nova,nikesh-mahalka/nova,alexandrucoman/vbox-nova-driver,apporc/nova,sridevikoushik31/nova,CloudServer/nova,dims/nova,OpenAcademy-OpenStack/nova-scheduler,Juniper/nova,mmnelemane/nova,gooddata/openstack-nova,maelnor/nova,SUSE-Cloud/nova,NeCTAR-RC/nova,MountainWei/nova,JianyuWang/nova,mgagne/nova,scripnichenko/nova,redhat-openstack/nova,akash1808/nova_test_latest,rickerc/nova_audit,cloudbase/nova-virtualbox,isyippee/nova,alaski/nova,orbitfp7/nova,yosshy/nova,devendermishrajio/nova,akash1808/nova,hanlind/nova,Juniper/nova,tianweizhang/nova,mandeepdhami/nova,Metaswitch/calico-nova,yrobla/nova,vmturbo/nova,klmitch/nova,sacharya/nova,Triv90/Nova,tianweizhang/nova,felixma/nova,Yuriy-Leonov/nova,jianghuaw/nova,j-carpentier/nova,Tehsmash/nova,maelnor/nova,projectcalico/calico-nova,yosshy/nova,devendermishrajio/nova_test_latest,whitepages/nova,Triv90/Nova,bgxavier/nova,rahulunair/nova,tudorvio/nova