🚨 New Python runtime environment in Heroku

[miss-islington]

There's a new Python runtime enviornment in Heroku. You might want to update the bot to use the new environment by editing the runtime.txt file.

See the changelog at https://devcenter.heroku.com/changelog-items/1679
Message:
Python 3.7.4 and 3.6.9 are now available on all stacks. See Heroku Python Support for more details.

The get-pip tool used by the Python Buildpack has also been updated.

(I'm a bot) 🤖

[Mariatta]

Stale.