Preparing for v1.0.0

[kaspth]

@andrewculver I think we should ship a v0.9.0 with the p deprecation, then we can merge #40 and prepare to ship v1.0.0, but give it a week for people to upgrade and find bugs if any.

How does that sound?

I'd be happy to handle this if you want to add me as an owner on RubyGems, though totally get it if not 😄

[andrewculver]

@kaspth This works for me!