Pipenv Support #569

Environment details

• OS type and version: macOS Big Sur 11.5.2
• Python version: python --version: 3.8.2
• pip version: pip --version: NA
• google-cloud-pubsub version: pip show google-cloud-pubsub: NA

Steps to reproduce

1. pipenv shell
2. pipenv install google-cloud-pubsub

Information

It would be nice if pipenv worked with this library. Right now, it gets stuck on the Locking... phase of pipenv (for a very long time, maybe hours). With the debug flag -v turned on, it shows a ton of Google Python libraries being installed during this time. It might be trying to rebuild the world instead of using binaries.