message: Remove duplicate imports
  Inside ffmpeg/__init__.py the last import line:
  ```
  from tensorflow.contrib.ffmpeg.ffmpeg_ops import decode_video
  ```
  is a duplicate of the previous import. This fix removes the duplicate.
diff: @@ -28,7 +28,6 @@ from __future__ import print_function
  from tensorflow.contrib.ffmpeg.ffmpeg_ops import decode_audio
  from tensorflow.contrib.ffmpeg.ffmpeg_ops import decode_video
  from tensorflow.contrib.ffmpeg.ffmpeg_ops import encode_audio
  -from tensorflow.contrib.ffmpeg.ffmpeg_ops import decode_video
  from tensorflow.python.util.all_util import remove_undocumented
  