Merge pull request heroku#912 from heroku/python-version-updates

Python version updates

Merge pull request heroku#907 from heroku/refactor-sqlite

Bug fix: fragile sqlite install

Merge pull request heroku#904 from heroku/sqlite-quickfix

Sqlite quickfix

Merge pull request heroku#894 from heroku/undo-revert

Reapply pipenv-ci bugfix

Merge pull request heroku#891 from heroku/python-27-update

Python 2.7.17

Merge pull request heroku#885 from heroku/new-pythons

Python 3.7.5 and 3.8.0

Merge pull request heroku#848 from heroku/cleanup-output

download get-pip silently

Merge pull request heroku#843 from heroku/hatchet/test-updates

Hatchet/test updates

Merge pull request heroku#831 from heroku/remove-cedar-tests

Remove cedar tests

Merge pull request heroku#827 from heroku/fix-python-3-5-7

Fix Python 3.5.7