Update Unity to release 2.4.1

tests/unity/.travis.yml

@@ -12,7 +12,9 @@ matrix:
 before_install:
   - if [ "$TRAVIS_OS_NAME" == "osx" ]; then rvm install 2.1 && rvm use 2.1 && ruby -v; fi
   - if [ "$TRAVIS_OS_NAME" == "linux" ]; then sudo apt-get install --assume-yes --quiet gcc-multilib; fi
-install: gem install rspec
+install:
+  - gem install rspec
+  - gem install rubocop
 script:
   - cd test && rake ci
   - make -s