1.Add "list_flavors" and "get_flavor" in api.
2.User "get_flavor" to get flavor name.
3.Add unittest for the new api function.
4.remove "ha_proxy" from package_matadata/openstack.conf
5.add flavor_config_validates
Change-Id: Ib17b851f5d8ac14b6d2bb13b0f44b575936c9f74