Fix get_diagnostics() test for no compute consumer
Fix get_diagnostics() test for no compute consumer

If we time out call()s in the fake RPC driver when there are no
consumers for a topic, the get_diagnostics() test fails when we attempt
to call() out to compute.

Mock up the get_diagnostics() rpcapi and verify it gets called.

blueprint: oslo-messaging
Change-Id: I4e33d089a9b01ea6dbe31ddf3c67c1733fce10aa

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