Update python-slugify to 3.0.3

[pyup-bot]

This PR updates python-slugify from 1.2.6 to 3.0.3.

Changelog

3.0.3

- Add Options to readme
- Add more unit tests

3.0.2

- Add official support of Py 3.7

3.0.1

- Add test.py to manifest

3.0.0

- Upgrade Unidecode
- Promote text-unidecode as the primary decoding package
- Add Unidecode as an optional extra. "pip install python-slugify[unidecode]"

2.0.1

- Add replacements option e.g. [['|', 'or'], ['%', 'percent'], ['-', '_']] (andriyor)

2.0.0

- Fix alternative dependency installation

Links

• PyPI: https://pypi.org/project/python-slugify
• Changelog: https://pyup.io/changelogs/python-slugify/
• Repo: https://github.com/un33k/python-slugify

[pyup-bot]

Closing this in favor of #268