fix the tests: can't compare qtys like that (...there is a util for this but I was lazy)
fix the tests: can't compare qtys like that (...there is a util for this
but I was lazy)

e-koch/spectral-cube,keflavich/spectral-cube,radio-astro-tools/spectral-cube,jzuhone/spectral-cube,low-sky/spectral-cube