Modifications to the release documentation for weekly releases - 663

I've proposed using the `homebrew install --devel` system for weekly releases, but I can't test that or update the hombrew-tap recipe until I have access to OS X  tomorrow. 

Fixes #663 
Refs #661
I think we want to be more specific with the glob. I think this glob will also pick up any sdists or wheels from commits after the tag, which we probably don't want to upload.