Hug

- Fixed issue 790 - Set Falcon defaults to pre 2.0.0 version to avoid breaking changes for Hug users until a Hug 3.0.0 release. The new default Falcon behaviour can be defaulted before hand by setting `__hug__.future = True`.

- Fixed issue 784 - POST requests broken on 2.5.0
- Optimizations and simplification of async support, taking advantadge of Python3.4 deprecation.
- Fix issue 785: Empty query params are not ignored on 2.5.0
- Added support for modifying falcon API directly on startup
- Initial `black` formatting of code base, in preperation for CI enforced code formatting

- Updated to latest Falcon: 2.0.0
- Added support for Marshmallow 3
- Added support for `args` decorator parameter to optionally specify type transformations separate from annotations
- Added support for tests to provide a custom host parameter
- Breaking Changes:
- Deprecated support for Python 3.4

- Add the ability to invoke the hug development server as a Python module e.g. `python -m hug`
- Corrected the documentation for the `--without-cython` install option

- Fixed issue 762 - HTTP errors crash with selectable output types
- Fixed MacOS testing via travis - added testing accross all the same Python versions tested on Linux

- Fixed API documentation with selectable output types