.travis.yml in rmagick-2.15.4 vs .travis.yml in rmagick-2.16.0

@@ -20,9 +20,11 @@
   - IMAGEMAGICK_VERSION=latest
 
 before_install:
   - source before_install_$TRAVIS_OS_NAME.sh
 
+install: bundle install --verbose
+
 rvm:
   - 1.8
   - 1.9
   - 2.0
   - 2.1