Change default service_type in tests to 'database'
Change default service_type in tests to 'database'

fixes bug 1131037

Change-Id: I6dd8125d7435a46299f038796ea040eae98bbd57

openstack/trove,changsimon/trove,citrix-openstack/build-trove,citrix-openstack-build/trove,cp16net/trove,cp16net/trove,mmasaki/trove,redhat-openstack/trove,zhujzhuo/openstack-trove,openstack/trove,citrix-openstack-build/trove,zhangg/trove,citrix-openstack/build-trove,citrix-openstack/build-trove,changsimon/trove,redhat-openstack/trove,hplustree/trove,redhat-openstack/trove,hplustree/trove,fabian4/trove,zhangg/trove,denismakogon/trove-guestagent,zhujzhuo/openstack-trove,denismakogon/trove-guestagent,zhujzhuo/openstack-trove,citrix-openstack-build/trove,changsimon/trove,fabian4/trove,cp16net/trove,fabian4/trove,mmasaki/trove,mmasaki/trove