Update flask-restful to 0.3.7

[pyup-bot]

This PR updates Flask-RESTful from 0.3.5 to 0.3.7.

Changelog

0.3.7

-------------

Released December 18, 2018

- Fix error handling in python3 ([696](https://github.com/flask-restful/flask-restful/pull/696))
- Fix arguments with type=list ([705](https://github.com/flask-restful/flask-restful/pull/705))
- Return code for `parse_args()` is now configurable ([722](https://github.com/flask-restful/flask-restful/pull/722))
- Removed `flask_restful.paging` module.
- Removed misleading `help_on_404` functionality ([722](https://github.com/flask-restful/flask-restful/pull/722))
- JSON keys are no longer sorted by default in debug mode in python3 ([680](https://github.com/flask-restful/flask-restful/pull/680))
- Various small fixes and updates to documentation

0.3.6

-------------

Released May 31, 2017

- `Argument.help` now supports unicode strings ([564](https://github.com/flask-restful/flask-restful/pull/564))
- Flags can now be passed to `inputs.regex` ([621](https://github.com/flask-restful/flask-restful/pull/621))
- Fix behavior of `action='append'` in conjunction with `location='json'` ([645](https://github.com/flask-restful/flask-restful/pull/645))
- `method_decorators` can be a `dict` to apply decorator behavior for only specific HTTP methods ([532](https://github.com/flask-restful/flask-restful/pull/532))
- JSON keys are no longer sorted by default in debug mode in python3 ([680](https://github.com/flask-restful/flask-restful/pull/680))
- Various small fixes and updates to documentation

Links

• PyPI: https://pypi.org/project/flask-restful
• Changelog: https://pyup.io/changelogs/flask-restful/
• Repo: https://www.github.com/flask-restful/flask-restful/