Should we consider a mac using macports instead of homebrew?

[larsbergstrom]

We discovered this weekend that somebody is still using macports: servo/servo#12672 (comment)

Should we consider adding a mac builder that has macports instead of homebrew? Since Travis does not support macports (https://docs.travis-ci.com/user/installing-dependencies/#Installing-Packages-on-OSX), I suspect that the rest of the ecosystem has basically zero testing for this configuration, so we'll need to check it at the servo/servo level if we want to enforce it.

[larsbergstrom]

Let's not do this. Should be a Tier-2 platform.