message: fix absl import issue
diff: @@ -48,7 +48,7 @@ DOCLINES = __doc__.split('\n')
  _VERSION = '1.12.0'
  REQUIRED_PACKAGES = [
  - 'absl-py >= 0.1.6',
  + 'absl-py >= 0.7.0',
  'astor >= 0.6.0',
  'gast >= 0.2.0',
  'google_pasta >= 0.1.1',
  