Adding the test case,test_healthmonitor:
Creates Lbaas pool with lb-method ROUND ROBIN, 3 members and vip
create the healthmonitor of type HTTP associate with the pool.
bringdown one of the backend server and verify requests are not
sent to that server and loadbalcing happens between the remaining backend servers
which are active, also verify requests stats getting forwarded once the server is up again.
Merge pull request #172 from stnaik/stnaik_lbaas

Adding the test case,test_healthmonitor: