message: Update Google Python Style Guide link
  Updated the link to Google Python Style Guide, it was pointing to the deprecated guide
  The new updated guide:
diff: @@ -107,7 +107,7 @@ diff <my_cc_file> /tmp/my_cc_file.cc
  #### Python coding style
  Changes to TensorFlow Python code should conform to
  -[Google Python Style Guide](https://google.github.io/styleguide/pyguide.html)
  +[Google Python Style Guide](https://github.com/google/styleguide/blob/gh-pages/pyguide.md)
  Use `pylint` to check your Python changes. To install `pylint` and
  retrieve TensorFlow's custom style definition:
  