Coveralls: Upload all coverage to coveralls.

[ryan-roemer]

• Hook up Coveralls account
• Add to Travis YML
• Track that coverage is generated by
  • Client
  • Server
  • Func

Basically like: https://github.com/FormidableLabs/full-stack-testing/blob/master/.travis.yml#L29-L33

  # Manually send coverage reports to coveralls.
  # - Aggregate client results
  # - Single server and func test results
  - ls coverage/client/*/lcov.info coverage/{server,func}/lcov.info | cat
  - cat coverage/client/*/lcov.info coverage/{server,func}/lcov.info | node_modules/.bin/coveralls || echo "Coveralls upload failed"