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.
Bump timeout for GenericHTTP Integration tests.
Merge pull request #152 from Nextdoor/issue_144

Bump timeout for GenericHTTP Integration tests.
Don't want for empty tasks.
Handle multiple transfer protocols in Macro actor.
Merge pull request #153 from Nextdoor/fix_terminate_empty

Don't want for empty tasks.
Major cleanup of Macro actor exceptions.

* Bring unit test coverage back to 100%
Retry current_instances call.
Increase retry for launch_server_array
Merge pull request #159 from Nextdoor/issue_138

Increase retry for launch_server_array
Merge pull request #158 from Nextdoor/issue_36

Retry current_instances call.
Launch up to min count, instead of new min count.
Handle Launching negative count.
Merge pull request #164 from Nextdoor/up_to_min

Launch up to min count, instead of new min count.
Download remote files in-memory.
Use tornado blocking http library for fetching macros.
Add sleep.json example for tests.