release 2020-03-01
Add macOS and Xcode jobs to the Travis CI matrix. Change-Id: Ib272919e3fc40e750db2930f9942bfbf6b59dc80 Reviewed-on: https://code-review.googlesource.com/c/re2/+/52672 Reviewed-by: Paul Wankadia <junyer@google.com>