Auto merge of #377 - mitchhentges:ci-tidy-all-flag, r=aneeshusa
Auto merge of #377 - mitchhentges:ci-tidy-all-flag, r=aneeshusa

Use --all flag when running `./mach test-tidy`

[`./mach test-tidy` should be `--faster` by default](https://github.com/servo/servo/issues/11217).
However, the [CI server should still check everything using the `--all` flag](https://github.com/servo/servo/pull/11267#issuecomment-220337310).

This PR changes the CI server to use the `--all` flag, but shouldn't be merged until Servo's [`11267`](https://github.com/servo/servo/pull/11267) gets merged, because `11267` adds `--all`

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ALikhachev/saltfs,UK992/saltfs,UK992/saltfs,servo/saltfs,rwaweber/saltfs,rwaweber/saltfs,UK992/saltfs,ALikhachev/saltfs,ALikhachev/saltfs,rwaweber/saltfs,servo/saltfs