Bump idna from 2.10 to 3.1

Bumps idna from 2.10 to 3.1.

Changelog

Sourced from idna's changelog.

3.1 (2021-01-04) ++++++++++++++++

• Ensure license is included in package (Thanks, Julien Schueller)
• No longer mark wheel has universal (Thanks, Matthieu Darbois)
• Test on PowerPC using Travis CI

3.0 (2021-01-01) ++++++++++++++++

• Python 2 is no longer supported (the 2.x branch supports Python 2, use "idna<3" in your requirements file if you need Python 2 support)
• Support for V2 UTS 46 test vectors.

Commits

• 8ba8151 Release v3.1
• 701239f Update history with recent PRs
• 47bc65e Include license in pypi tarball (#92)
• 8403413 Drop universal bdist_wheel option (#93)
• 6bd89af Test on PowerPC with Travis CI (#91)
• a45bf88 Release v3.0
• 82f7b70 Fix regressions from removing Python 2 support
• 229f123 Use Github Actions for unit testing
• d8bb757 Merge pull request #90 from kjd/fix-licensing
• a2f5460 Merge branch 'master' into fix-licensing
• Additional commits viewable in compare view