Use carthage boostrap rather than update

Author: Tom Kemp

.travis.yml

@@ -15,7 +15,7 @@ before_install:
       brew install carthage;
     fi
   - gem install xcpretty --no-document
-  - carthage update --no-use-binaries
+  - carthage bootstrap --no-use-binaries
   - SIMULATOR_ID=$(xcrun instruments -s | grep -o "$DEVICE \[.*\]" | grep -o "\[.*\]" | sed "s/^\[\(.*\)\]$/\1/")
   - echo "$SIMULATOR_ID"
 before_deploy: