Remove unused nova/api/mapper.py
Remove unused nova/api/mapper.py

Introduced recently by 60ff2e, but seems totally unused.

Change-Id: Iefe0168b6bc189ec83efbd69f0be22946696d408

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