Document how often the software stack is updated

[jkrick]

And how would a user know when the stack was or will be updated?
ie., if I run into some bug and find that a newer version of astropy might fix that bug, how will I know if this is already in the works, or if I need to request it.

for this same use case, might also want to document how to manually upgrade at the top of a users notebook, while waiting for the software stack to come into sync.