Upgrade Travis MacOS version

GenieTim · web-flow · commit abbc3c7d2aa2 · 2019-01-27T18:12:12.000+01:00
diff --git a/.travis.yml b/.travis.yml
@@ -13,7 +13,7 @@ perl:
 matrix:
   include:
     - os: osx
-      osx_image: xcode7.3
+      osx_image: xcode9.4
       language: generic
       perl: 5.24
   allow_failures:
