.travis.yml in unasukecop-0.4.0 vs .travis.yml in unasukecop-0.5.0

@@ -1,5 +1,10 @@
+notifications:
+  email: false
+dist: trusty
 sudo: false
 language: ruby
 rvm:
   - 2.3.3
-before_install: gem install bundler -v 1.14.3
+  - 2.4.1
+before_install: gem install bundler
+script: bundle exec rubocop