fix(pyup): Update pre-commit to 2.20.0

[pyup-bot]

This PR updates pre-commit from 2.19.0 to 2.20.0.

Changelog

2.20.0

===================

Features
- Expose `source` and `object-name` (positional args) of `prepare-commit-msg`
hook as `PRE_COMMIT_COMIT_MSG_SOURCE` and `PRE_COMMIT_COMMIT_OBJECT_NAME`.
 - 2407 PR by M-Whitaker.
 - 2406 issue by M-Whitaker.

Fixes
- Fix `language: ruby` installs when `--user-install` is set in gemrc.
 - 2394 PR by narpfel.
 - 2393 issue by narpfel.
- Adjust pty setup for solaris.
 - 2390 PR by gaige.
 - 2389 issue by gaige.
- Remove unused `--config` option from `gc`, `sample-config`,
`validate-config`, `validate-manifest` sub-commands.
 - 2429 PR by asottile.

Links

• PyPI: https://pypi.org/project/pre-commit
• Changelog: https://pyup.io/changelogs/pre-commit/
• Repo: https://github.com/pre-commit/pre-commit