This patch adds jsonschema validation for below Group types API's
* POST /v3/{project_id}/group_types
* PUT /v3/{project_id}/group_types/{group_type_id}
Made changes to unit tests to pass body as keyword argument as wsgi
calls action method [1] and passes body as keyword argument.
[1] https://github.com/openstack/cinder/blob/master/cinder/api/openstack/wsgi.py#L997
Change-Id: I0dde39ec96b04e497553b07a07acb95039ee5959
Partial-Implements: bp json-schema-validation