docs(client): update with dev CLI binaries and local deis.py suggestion

Didn't realize the versioning issue in #1671 would crop up so fast, so hopefully this alleviates the pain for users who rely on our CLI binaries.
Yeah...ok. I think people shouldn't be installing anything to the system python, is why I didn't add `sudo`. Virtualenv FTW, but I didn't want to explain that either. :)