Use default Travis OS X image

lgeiger · lgeiger · commit 7edbdd47b31d · 2016-10-07T00:44:03.000+02:00
diff --git a/.travis.yml b/.travis.yml
@@ -15,8 +15,6 @@ os:
   - linux
   - osx
 
-osx_image: xcode7.2
-
 env:
   matrix:
     - NODE_VERSION="6"
