Releasing shopify_python_api

1. Check the Semantic Versioning page for info on how to version the new release: http://semver.org

2. Update version in shopify/version.py

3. Update CHANGELOG entry for the release.

4. Commit the changes
    git commit -m "Release vX.Y.Z"

5. Tag the release with the version
    git tag -m "Release X.Y.Z" vX.Y.Z

6. Push the changes to github
    git push --tags origin master

7. Shipit!