message: Remove `sudo: required` from `.travis.yml`
  Summary:
  This is just backported to `fbcode_builder`.
  snarkmaster
  Pull Request resolved:
  Test Plan: Push and watch Travis
diff: # Facebook projects that use `fbcode_builder` for continuous integration
  # share this Travis configuration to run builds via Docker.
  -sudo: required
  -
  # Docker disables IPv6 in containers by default. Enable it for unit tests that need [::1].
  before_script:
  - if [[ "$TRAVIS_OS_NAME" != "osx" ]];
  