Disable upgrading Carthage temporarily

.travis.yml

@@ -3,9 +3,9 @@ osx_image: xcode8
 cache:
   directories:
   - Lib/vendor/bundle
-before_install:
-- brew update
-- brew outdated carthage || brew upgrade carthage
+# before_install:
+# - brew update
+# - brew outdated carthage || brew upgrade carthage
 install:
 - "(cd Lib && bundle install --path=vendor/bundle --binstubs=vendor/bin)"
 before_script: