Set up Bintray and Circle CI to build and deploy binaries

[chebizarro]

The RxBarcodeScanner is a generally useful library outside of the Reference Point Navigation client app so it will be maintained as a separate package. To make it easy to integrate this, the Circle CI -> Bintray pipeline needs to be set up.

This instructions here are pretty straightforward. I have set up a Bintray organization here. A new Bintray account separate from my own should be set up for the organization.