specutils 1.5 breaks DRAGONS 3.0.x (and master)

[KathleenLabrie]

Just a note so that we don't forget. It was found today (by Chris) that specutils 1.5 breaks 3.0.x. While that gets sorted out (probably a big job), the workaround for users is to revert to specutils v1.1.

v1.5 is currently only available on conda-forge. We tell the users to use the astroconda channel and that has only 1.1, so that mitigates the problem a bit.