Package management is hard. Sometimes in Python package development, your local (development) environment may behave a little differently than a deployment target. Below is a simple method I use to replicate a clean environment and test Python package installs and tests.
Sometimes Travis CI builds fail due to sporadic timeouts, network errors, etc. While these non-code errors can be quite annoying, Travis CI has a handy
Restart build for when these situations occur, but only users with admin privileges have access to this feature.