.travis.yml in fluent-plugin-chatwork-1.0.0 vs .travis.yml in fluent-plugin-chatwork-1.0.1

@@ -1,9 +1,10 @@
 language: ruby
 rvm:
 - 2.1
 - 2.2
 - 2.3.3
+- 2.4.0
 - ruby-head
 cache: bundler
 bundler_args: --jobs=2
 before_script:
 - export CODECLIMATE_REPO_TOKEN=93805166d8380e3602f18bd68762cb0222f0d68fca3f1771f22188a5a0995485