SDSS module includes data on install

[djperrefort]

Problem

The SDSS spectroscopic data release sako18_spec is published using .fits files in IRAF format. I've yet to figure out how to parse the wavelength values from these files reliably in Python. At present the sako18_spec includes compressed .txt versions of these files that have been pre-parsed using IRAF. Including survey data in the installation process is against the overall design of the package.

Expected Behavior

No SDSS data should be included with the package on install. Data should be downloaded using the download_module_data function.

Potential Solutions

1. Host the pre-parsed files online. This isn't ideal as it opens the door for having to host other data, which is an unwanted responsibility.
2. Download the SDSS spectra as fits files and figure out how to parse the IRAF format.