osclient: Pass endpoint_type in kw_args to client
osclient: Pass endpoint_type in kw_args to client

Heatclient expects a value for endpoint_type from kw_args or it
uses None. Rally.osclient does not pass endpoint_type to the
heatclient. To rectify this, the endpoint_type variable is
explicitly placed in kw_args and kw_args passed to
the Heat client constructor.

Change-Id: I34d826f4be449a58dbe0c939efecf42d6ffa9d3e

openstack/rally,openstack/rally,yeming233/rally,yeming233/rally,openstack/rally,openstack/rally