Update dependencies

[elevenfive]

What?

Pull in latest plugin and dependency versions; address deprecation warnings.

Why?

Stay up-to-date with the build ecosystem before things snowball and the project won't work with future Android Studio updates.

How?

Update versions of dependencies and add plugin (https://github.com/ben-manes/gradle-versions-plugin) to make dependency version checking easier.

Testing?

Build, run, tap around