update travis.yml osx_image

Andrew Lloyd · web-flow · commit 0fc6b4b61eb7 · 2017-11-10T12:01:26.000Z
diff --git a/.travis.yml b/.travis.yml
@@ -1,5 +1,5 @@
 language: objective-c
-osx_image: xcode8.1
+osx_image: xcode9.1
 branches:
   only:
     - master
