Please create a pull request against master.
Try to make the code in the pull request as focused and clean as possible. The code should conform to PEP8 also pass pyflakes as defined in https://github.com/prezi/python-zipkin/blob/master/.travis.yml#L45-L46.
By contributing your code, you agree to license your contribution under the terms of the Apache 2 License https://github.com/prezi/python-zipkin/blob/master/LICENSE.txt