Add python-gitlab

[max-wittig]

If you're adding a project to the Python 3 statement, please ensure you have:

• Discussed dropping Python 2 support with all maintainers
• Discussed signing the statement with all maintainers
• Added a suitable logo if the project has one
  • Approximately square logos generally fit better than banners
  • Compressed the logo to save bandwidth (run scripts/squash-images.sh on it)
• Checked the Netlify preview made from the pull request

[takluyver]

Thanks! The projects are ordered by stars count, so you can move it much further up the list - just after h5py, I think.

(Checked that @max-wittig is the main maintainer of python-gitlab)

[max-wittig]

@takluyver Thanks for the review. Order changed now.

[takluyver]

Thanks, and welcome aboard!

[max-wittig]

@takluyver Thank you. Looking forward to 2020-01-01 😄