Provide way to update a hutch's hutch-python from the template

[ZLLentz]

Expected Behavior

If the template improves it should be trivial to update a hutch's setup automatically rather than having to do it manually

Current Behavior

Usually I just create a brand new hutch-python directory for the hutch and copy over the files I care to update

Possible Solution

Create a script that creates a /tmp version of the python env and copies over the stuff you want to update
Maybe like hutch-python --update xppenv

Context

This is always a pain