Travis: enable macOS builds
commit515d190b2ca9249871d04067c3bdbd312669997e
authorteor <teor@torproject.org>
Thu, 9 Aug 2018 08:03:18 +0000 (9 18:03 +1000)
committerteor <teor@torproject.org>
Thu, 9 Aug 2018 12:17:50 +0000 (9 22:17 +1000)
treeee70f89f5a5bfbbda3b1a2e0c8cb16e845122fcc
parentc53f17fb1a3b787567cee1e87f03a887a5cee0bd
Travis: enable macOS builds

Also:
* explain why we don't install zlib

Part of 24629.
.travis.yml