pyup: Scheduled weekly dependency update for week 34

[pyup-bot]

Update sphinx-tabs from 1.1.13 to 1.2.1.

Changelog

1.2.1

🐛 FIX: Remove `app.add_javascript` use for sphinx v2

1.2.0

`sphinx-tabs` has now moved to the [EBP organisation](https://executablebooks.org) 🎉

Deprecated 🗑

- Python < 3.5 and Sphinx < 2 support dropped

Improved 👌

- Lots of code and CI restructuring (see [EBP Migration (76)](https://github.com/executablebooks/sphinx-tabs/commit/6342ed3f1f7d4cb50891001f26d4e3c4c08ee422))

Fixed 🐛

- Replace `add_javascript` by `add_js` for sphinx>=3 (removes warning!),
thanks to [Daltz333](https://github.com/Daltz333)

Links

• PyPI: https://pypi.org/project/sphinx-tabs
• Changelog: https://pyup.io/changelogs/sphinx-tabs/
• Repo: https://github.com/executablebooks/sphinx-tabs