Move all nettests from data/ directory to the ooni/nettests directory.
Add support for specifying nettests via their shorthand name.
Update documentation and test decks to use shorthand for tests.
Only lookup test decks if they have not already been specified.
Merge remote-tracking branch 'thetorproject/master' into feature/move_nettests

* thetorproject/master:
  Add encoding format
  Add a version and author to dnsspoof
  Write unittest for testing https://github.com/TheTorProject/ooni-backend/pull/16
  URL must be utf-8
Merge branch 'master' into feature/move_nettests

* master:
  Enforce str on IP address of backend.
  Change the default ports used by Tor.
Only lookup and set collectors when it is needed.
Implement retry logic inside of the oonibclient.
Handle exceptions in backend queries better.
Merge pull request #203 from TheTorProject/fix/test_helper_lookup

Fix/test helper lookup