.travis.yml in typogen-0.2.0 vs .travis.yml in typogen-0.2.1

@@ -3,6 +3,7 @@
 rvm:
   - 2.0
   - 2.1
   - 2.2
   - 2.3.3
-before_install: gem install bundler -v 1.14.3
+  - 2.4.0
+before_install: gem install bundler -v 1.15.1