Why are these changes needed?

Related issue number

I've run scripts/format.sh to lint the changes in this PR.
I've included any doc changes needed for https://docs.ray.io/en/latest/.
I've made sure the tests are passing. Note that there might be a few flaky tests, see the recent failure rates at https://ray-travis-tracker.herokuapp.com/.
Testing Strategy
- Unit tests
- Release tests
- This PR is not tested (please justify below)