Bump papermill from 2.6.0 to 2.7.0

Bumps [papermill](https://github.com/nteract/papermill) from 2.6.0 to 2.7.0.
- [Changelog](https://github.com/nteract/papermill/blob/main/docs/changelog.md)
- [Commits](nteract/papermill@2.6.0...2.7.0)

---
updated-dependencies:
- dependency-name: papermill
  dependency-version: 2.7.0
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]