Post-release Avatica 1.7.0 TODO

[Josh Elser]

Logging what I've done (just in case I missed something along the way)
* Wrote up a new article for avatica 1.7.0
* Pushed artifacts to dist.a.o/release for pubsub to do its thing
* Released maven staging repo
* Sent [RESULT]
* Updated Calcite's avatica.version to 1.7.0

I think at this point, I just need to wait for pubsub to do its thing 
and then:

* send msg to announcement@a.o
* Publish avatica website
* Send something out via Twitter
* Find a beer?

- Josh