requires xcode 10, apparently, for optional.

2019-12-10 23:09:04 -05:00 · 2019-12-10 23:09:04 -05:00 · e3aa60be6a
parent 3aab0a4735
commit e3aa60be6a
1 changed files with 1 additions and 0 deletions
--- a/.travis.yml
+++ b/.travis.yml
@ -1,4 +1,5 @@
 dist: bionic
+osx_image: xcode10
 language: cpp
 os:
  - osx