message: Update MANIFEST.in
  Include superset-frontent/package.json in package because setup.py requires it
diff: @@ -18,6 +18,7 @@ include NOTICE
  include LICENSE.txt
  graft licenses/
  include README.md
  +include superset-frontend/package.json
  recursive-include superset/examples *
  recursive-include superset/migrations *
  recursive-include superset/templates *
  