.travis.yml in rack-blogengine-1.0.6 vs .travis.yml in rack-blogengine-1.0.7

@@ -1,7 +1,12 @@
 language: ruby
 cache: bundler
 
+before_install:
+  - gem update --system
+  - gem --version
+  - gem install bundler
+
 rvm:
   - 2.0.0
   - 2.1.0
   - 2.1.1
   - ruby-head