message: Bump absl-py to pick up py3.8 logging fix.
diff: @@ -52,7 +52,7 @@ from setuptools.dist import Distribution
  _VERSION = '2.4.0'
  REQUIRED_PACKAGES = [
  - 'absl-py >= 0.7.0',
  + 'absl-py >= 0.9.0',
  'astunparse == 1.6.3',
  'flatbuffers >= 1.12',
  'gast == 0.3.3',
  