message: Freeze gast==0.2.2 in setup.py requirements.
  This fixes breakage caused by minor update breaking tensorflow.
diff: @@ -54,7 +54,7 @@ REQUIRED_PACKAGES = [
  'astor >= 0.6.0',
  'backports.weakref >= 1.0rc1;python_version<"3.4"',
  'enum34 >= 1.1.6;python_version<"3.4"',
  - 'gast >= 0.2.0',
  + 'gast == 0.2.2',
  'google_pasta >= 0.1.6',
  'keras_applications >= 1.0.8',
  'keras_preprocessing >= 1.0.5',
  