Add spectrumplot tutorial data cube to astropy-data

[kakirastern]

For the spectrumplottutorial to be added to Learn Astropy. The most important content here is the data cube fits file.

[bsipocz]

@kakirastern - I think only the fits file should end up in this reposity from this PR. Both the scripts and rst docs should live in the tutorials repo. Same for the image, or in fact best would be to not even store the image but generate on the spot.

[kakirastern]

Hi @bsipocz Agreed. Have removed all files except the FITS file for the data cube to be used in the spectrumplot tutorial in this PR.

[bsipocz]

Thanks for the quick follow-up.

I would like to see the review for the tutorial itself, in astropy/astropy-tutorials#423, before merging the file into this repo.

Also, it doesn't have to be now, but squashing the two commits is favourable to keep the unrelated files out of the history.

[kakirastern]

Not a problem! Have just squashed the commits into one before I forget. I will probably get back to this PR once the PR astropy/astropy-tutorials#423 has been reviewed.

[bsipocz]

Thanks. Basically the main thing I need from that review that this is the ideal file for the purposes of the tutorial (and/or possible reuses for future tutorials)

[kakirastern]

Sure, will be careful to let the repo maintainers know. They are indeed aware that I have been working on the tutorial even though no review for it has been made yet.

[kakirastern]

Apologies for the delay, but we have had some protracted discussions regarding where to store the concerned data file for a new Learn Astropy tutorial for the past few weeks. As a decision has been reached in last week's Learn Astropy meeting, I will follow up on this soon after updating the code in the tutorial notebook to download the temporary link instead.

[eteq]

closed at request of the author - last SHA 216305a