Use jsonschema for testing queue

Validate response of listing queues (GET /queue) with jsonschema in
functional tests. Also the signature of assertSchema was changed:
now it accepts not the schema itself, but its name. It was done to
simplify its usage in test cases.

Partially implements: blueprint jsonschema-validation

Change-Id: Ic48236607746eae088300ff7a6f787622a2156f7
Merge "Use jsonschema for testing queue"