Issue Template

Title: Mac builds time out if bazel brew pkg is not found

Description:
The Bazel homebrew package is currently missing for any version post 0.15.2 . @moderation found the upstream problem is that the Bazel team has not enabled core homebrew packages outside of their own tap.

The Mac build will currently attempt a bazel compile from source if it the homebrew install fails. If this takes over 10 min, it will fail the whole build.

I'm wondering if we should leverage the working Bazel tap for now in order to prevent the timeouts until the core homebrew repo is updated.

Thoughts? @htuch @ggreenway @moderation