Fail tests early if mongod is not found
Fail tests early if mongod is not found

Instead of letting the tests report connection errors,
check for the mongod process early and don't run the
tests at all if it is not found.

Change-Id: Iebf420ba62954ffe0d2b9c23375c9a0ff9673845

citrix-openstack-build/ceilometer,idegtiarov/ceilometer,NeCTAR-RC/ceilometer,rickerc/ceilometer_audit,r-mibu/ceilometer,m1093782566/openstack_org_ceilometer,tanglei528/ceilometer,JioCloud/ceilometer,eayunstack/ceilometer,openstack/ceilometer,openstack/aodh,ityaptin/ceilometer,eayunstack/ceilometer,cernops/ceilometer,redhat-openstack/ceilometer,JioCloud/ceilometer,idegtiarov/ceilometer,mathslinux/ceilometer,isyippee/ceilometer,redhat-openstack/ceilometer,tanglei528/ceilometer,sileht/aodh,MisterPup/Ceilometer-Juno-Extension,rackerlabs/instrumented-ceilometer,pkilambi/ceilometer,rackerlabs/instrumented-ceilometer,cernops/ceilometer,maestro-hybrid-cloud/ceilometer,sileht/aodh,NeCTAR-RC/ceilometer,ityaptin/ceilometer,froyobin/ceilometer,mathslinux/ceilometer,rickerc/ceilometer_audit,m1093782566/openstack_org_ceilometer,chungg/aodh,pkilambi/ceilometer,r-mibu/ceilometer,NeCTAR-RC/ceilometer,maestro-hybrid-cloud/ceilometer,rackerlabs/instrumented-ceilometer,Juniper/ceilometer,luogangyi/Ceilometer-oVirt,pczerkas/aodh,citrix-openstack-build/ceilometer,luogangyi/Ceilometer-oVirt,rickerc/ceilometer_audit,Juniper/ceilometer,MisterPup/Ceilometer-Juno-Extension,pczerkas/aodh,openstack/ceilometer,openstack/aodh,JioCloud/ceilometer,fabian4/ceilometer,fabian4/ceilometer,tanglei528/ceilometer,citrix-openstack-build/ceilometer,froyobin/ceilometer,isyippee/ceilometer,chungg/aodh