Fix wrong url in update_avatar spec stub request
Fix wrong url in update_avatar spec stub request

- updated incorrect url so that the spec would stub correctly
- also added 2nd stub for the put request so that the test wouldn't fail
  when it couldn't find the discourse development server.

techAPJ/discourse_api,oblakeerickson/discourse_api,thieunus/discourse_api,spatten/discourse_api,Odyl/discourse_api,discourse/discourse_api,melissawahnish/discourse_api,maclover7/discourse_api,RyzacInc/discourse_api,jmay/discourse_api