New archive request: GTC / Gran Telescopio Canarias

[privong]

If possible, it would be nice to have an astroquery interface to the GTC archive. The web form for that is located here: https://gtc.sdc.cab.inta-csic.es/gtc/jsp/searchform.jsp I'm not aware if there are other interfaces.

[bsipocz]

Sure, it sounds like a useful addition and we'll code review it if someone is interested in working on a PR for it.