Test Timeouts in Travis

[Stu Hood]

Hey gang!

Test timeouts will now be applied in travis, which should hopefully result in more useful error messages: see https://github.com/pantsbuild/pants/pull/8110

If you encounter a failing shard, please help everyone out by (before restarting it!) locating the failing test and then:

• If it timed out:
• see whether the timeout can be adjusted upward (the max timeout in Travis is now 540 seconds in order to time out in a way that will get a useful error message) and maybe bump it in your PR.
• If it didn't timeout, or the timeout can't be adjusted, consider bumping or creating a flaky-test issue.

Thanks!

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@stuhood