.travis.yml in xi-lang-0.2.1 vs .travis.yml in xi-lang-0.2.2

@@ -1,5 +1,5 @@
 sudo: false
 language: ruby
 rvm:
-  - 2.3.1
-before_install: gem install bundler -v 1.13.6
+  - 2.4
+before_install: gem install bundler -v 1.17.2