message: Use ubuntu for the check
diff: @@ -55,7 +55,7 @@ jobs:
  - job: Check
  pool:
  - vmImage: "macos-10.14"
  + vmImage: "ubuntu-16.04"
  variables:
  rust_toolchain: nightly-2019-06-10
  condition: in(variables['Build.SourceBranch'], 'refs/heads/master', 'refs/heads/staging', 'refs/heads/trying')
  