Add misc.Macro to execute additional JSON files

* Moving all the code from deploy.py to this Macro actor
  and using it for actual deployments.
Add misc.Macro integration test.

* Uses misc.Sleep as a test of inside of the json
Add documentation to misc.Macro
Improve misc.Macro documentation.
Handle multiple transfer protocols in Macro actor.
Major cleanup of Macro actor exceptions.

* Bring unit test coverage back to 100%
Download remote files in-memory.
Use tornado blocking http library for fetching macros.
Merge branch 'master' into macro_actor
Tidy up demjson error reporting.
Import Macro class directly in deploy.py
Use github sleep.json file from master branch.
Allow json as a positional argument.
Add debug representation for StringIO buffer.
Tidy up deploy.py
Add unit test for convert_json_to_dict
Merge pull request #151 from Nextdoor/macro_actor

Add misc.Macro actor
Merge pull request #167 from Nextdoor/rc_0.3.0

Rc 0.3.0