Patch by justincohen@, uploaded by phoglund@.
This moves our trybots to 10.13+, which is required for xcode 10,
which is now required by the build scripts.
Bug: None
Change-Id: I77d47bcb6696d290a397b098966ecc4ea1c0aeb9
Reviewed-on: https://webrtc-review.googlesource.com/97301
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24661}