add codecov.yml for codecov settings (#438)
add codecov.yml for codecov settings (#438)

Settings for codecov can now be configured with a YAML file in the repository rather than through their website. 
https://github.com/codecov/support/wiki/codecov.yml
MarcoLotz/docker-client,spotify/docker-client,spotify/docker-client,MarcoLotz/docker-client,rgrunber/docker-client,rgrunber/docker-client