Began warning implementation, added a new balrog image class variable `version` to handle DES data versions (default to our case of y3v02), and created the `_set_zeropoint()` method for `chip` #11.
Began warning implementation, added a new balrog image class variable `version` to handle DES data versions (default to our case of y3v02), and created the `_set_zeropoint()` method for `chip` #11.

sweverett/Balrog-GalSim,sweverett/Balrog-GalSim