.travis.yml in gistory-0.1.5 vs .travis.yml in gistory-0.1.6

@@ -2,7 +2,6 @@
 language: ruby
 rvm:
   - 2.4.0
   - 2.3.3
   - 2.2.6
-  - 2.1.10
-before_install: gem install bundler -v 1.14.3
+before_install: gem install bundler -v 1.17.3