change osx travis-ci image to xcode11

The default image is broken with respect to shellcheck. The fix was found at https://travis-ci.community/t/xcode-8-3-homebrew-outdated-error/3798
eellak · Jul 20, 2019 · 2638281 · 2638281
1 parent 311865f
commit 2638281
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/.travis.yml b/.travis.yml
@@ -15,3 +15,5 @@ script: make test
 os:
   - linux
   - osx
+
+osx_image: xcode11