.travis.yml in vnstat-ruby-1.1.0 vs .travis.yml in vnstat-ruby-2.0.0

@@ -1,11 +1,13 @@
+sudo: false
 language: ruby
 rvm:
- - '2.0.0'
- - '2.1.7'
- - '2.2.3'
- - '2.3.1'
- - '2.4.1'
+ - '2.1.10'
+ - '2.2.8'
+ - '2.3.6'
+ - '2.4.3'
+ - '2.5.0'
+before_install: gem install bundler -v 1.14.6
 script: bundle exec rspec
 addons:
   code_climate:
     repo_token: 06a44082b0f5a5114eec226952c45443a4ac8c86e59e098869b5c07e420505ab