Delete DataOneV1

[oxinabox]

Re #67 (comment)

[oxinabox]

the combining failure is because now there is one less generator and the results are different.
Semantically they are the same, but since the different providers do things like http vs https for the website that does change the reference.
So that needs to be regenerated.

[oxinabox]

while fixing this I noticed that our DataDryad generator wasn't working for DOIs, which I fixed,
and added tests.

Also I think this will fail, as I think the DataCite API is down
cf: https://twitter.com/oxinabox_frames/status/1056115555499823105
Update: yes indeed it is down.

[oxinabox]

Tests passing.
@SebastinSanty do you want to review it?

[SebastinSanty]

Sure, I'll check

[SebastinSanty]

LGTM