- no longer checks for "date_obs"; calculate that yourself
- also adds "sdss_id" to metadata now

…ases

- added new test cases for BOSS-only mwmVisit and mwmStar files
- added new checks to SpectrumList mwmVisit/mwmStar test to check verified filetype is correct
- forced override on default SpectrumList loaders -- now SpectrumList is no longer ambiguous and doesn't require a format specification
  - relevant areas in tests are updated accordingly
- added print warnings to when HDU is not specified on Spectrum1D loaders for files with multiple spectra.
- ensured tests now remove tempfiles with os.remove
  - arguably, this could work better with tmpfile, but i don't know how tests are deployed on the server-side

- three points outlining changes listed in PR as per astropy#1185

Co-authored-by: Brian Cherinka <[email protected]>

- all loaders now only load for a single datatype, avoiding prior knowledge of SDSS datatypes
- updated to only load as SpectrumList
- updated to load all visits in mwmVisit files as individual Spectrum1D objects in the SpectrumList
- relevant tests removed
- relevant import __all__ adjusted

…ss-loaders into mwmvisit-boss-fix

- describes changes shown previously

revert back to 4bee136

- readded print -> warnings conversion
- can specify the visit to load on mwmVisit load.
- added relevant tests for the new mwmVisit case

…ss-loaders into mwmvisit-boss-fix

- no longer unpacks nD spectrum in all cases for mwm
- will still unpack flux from 2D to 1D in the event its single visit or coadd

…ss-loaders into mwmvisit-boss-fix

- fixed flux array length check so that the 2D mwm visits are checked properly

- removed HDU is empty warning on mwm SpecList, not really worth a warning
- moved test cases which are designed to throw exceptions into their own test function