Python 2.x and 3.x iterate dicts in different orders, which has implications for assembling query strings. We have several tests which spy on `urlopen` and return fake payloads, which were failing when run on Python 3. This change adds sorting to the querystring parameters before we assemble them into a URL, and fixes up the test URLs to use those. Testing Done: Ran unit tests or Python 2.7 and 3.9.