Events plugin: stop requesting events from Meetup.com

[harding]

Closes #1617

In testing, the only rendered HTML changes to the site were three fewer lines of whitespace per rendered translation of the Events page.

I also checked the Events RSS feed and it appeared that we never included any Meetups information in it, so no changes were required there.

[wbnns]

@harding Thanks

Unless others object, this will be merged on Wednesday, June 7th.

[Mirobit]

@harding Submitted a pull request updating the docs regarding the removal of meetup.

[harding]

@Mirobit thanks for catching that! I added your commit a492959 to this branch, but GitHub isn't showing it here (and isn't showing it as merged on your PR), even though it does show on the branch itself. I think this is a bug in GitHub, so I'll wait a few hours to see if it resolves itself before poking at it.

Thanks again!

[harding]

Seems to be mostly working now. @Mirobit's commit is showing on this page and in the diff view, but Travis is not checking it (not that it should---the internal site docs are not checked).

@wbnns I think this remains ready for Wednesday merge, baring objections, but please feel free to move back the planned merge if you want to give others a chance to review the additional commit.