Update setup scripts to be more CI and pip friendly

[gbrammer]

See the update-setup branch.

TBD:

• how to include the pieces from the eazy-photoz submodule that are currently symlinked in eazy/data
• how to include the dependencies of my github clones of the dust_extinction and dust_attenuation packages

[gbrammer]

@jdavies-st, @ivastar Do you have any suggestions for the items above?

[ivastar]

@gbrammer which pieces of eazy-photoz do you need for eazy-py? Are you just using the static files (templates, filters, etc.) or do you need for the C modules to be compiled?

[ivastar]

• See Download function for templates #21 for a possible alternative to including eazy-photoz as a submodule.
• Your version of dust_extinction seems to be the same as the original. Can you just include the pip-released version in the setup.cfg file?
• For dust_attenuation, I'd open a pull request against the repo, seems like most of the changes are big fixes.