CircleCI build status, and Apache 2.0 license badges added to UI readme.

Repo presently configured in Coveralls for just the line coverage for the Go server code, and not including a code coverage badge with this task (Investment of time to investigate tooling and implement multi-language; golang, javascript, code coverage for the react ui code does not seem warranted at this time, and can be included in a future task if required).

cc David Ffrench