fix(transport.wsgi): JSON home doc missing GET and HEAD hints

GET and HEAD support was added for /v1/queues/{queue_name} but
the home document was not updated accordingly. This patch adds
those methods (AKA verbs) to the home document.

Change-Id: I82bbbf1b6d0735dc2d15faee715175fc724b9423

marconi/transport/wsgi/v1.py

@@ -42,7 +42,7 @@ JSON_HOME = {
                 'queue_name': 'param/queue_name',
             },
             'hints': {
-                'allow': ['PUT', 'DELETE'],
+                'allow': ['GET', 'HEAD', 'PUT', 'DELETE'],
                 'formats': {
                     'application/json': {},
                 },