document running a small set of tests
document running a small set of tests

Change-Id: I63807c580ad962127c6eaa3dc7e78fbe7ce2263f
Closes-Bug: #1347773

zhangg/trove,cp16net/trove,mmasaki/trove,changsimon/trove,zhujzhuo/openstack-trove,redhat-openstack/trove,openstack/trove,changsimon/trove,hplustree/trove,changsimon/trove,mmasaki/trove,mmasaki/trove,cp16net/trove,zhujzhuo/openstack-trove,fabian4/trove,hplustree/trove,fabian4/trove,openstack/trove,redhat-openstack/trove,zhangg/trove,cp16net/trove,fabian4/trove,zhujzhuo/openstack-trove,redhat-openstack/trove