Add voting to release process

[Cantor, Scott]

> My motivation for this is to make sure our efforts are coordinated,
> especially since we have less frequent dev calls now.

Historically it hasn't been needed because the work on each piece was dominated by one person, but I agree the IdP needs it.

> I guess it would be nice if the release notes for the release were
> figured out for the release vote, so folks can have a better idea of
> what they are voting for.

I was planning to start work on the release notes for 3.1 shortly so I didn't forget what to note.

We have another decision to make. Chad's plan was to clone the wiki space each minor release, which is why the original is IDP30. I was never particularly fond of that idea because I think it breaks link stability, but we can't rename the space Key, so it's either clone it or just deal with the name being weird.

-- Scott