Polyswarm-api

In this release, we add support for metadata searching and updates for our most recent API release.

New Features

- Adds metadata searching support via ElasticSearch queries.
- Re-add support for Python v3.5
- Begin adding unit-testing
- Improve documentation

Fixes
- Address issue with stream URL
- Support various API endpoint changes
- Assorted minor bugfixes in search output formatting

* Fix reported issue with `rescan` functionality that incorrectly returns an error, though the scan started.
* Fix reported issue with `search` functionality that printed an erroneous error when hash wasn't found.

* Support hunt status reporting
* Miscellaneous bugfixes and cleanup

* Include requirements.txt in the source bundle on pypi to enable source package installation to work.
* Return to 3 digit versioning.