Update travis-ci

repeatedly · repeatedly · commit 1b4f95cc3ecd · 2019-12-20T13:35:42.000+09:00
diff --git a/.travis.yml b/.travis.yml
@@ -15,7 +15,7 @@ gemfile:
  - Gemfile
 
 before_install:
-  - gem update --system
+  - gem update bundler
 
 before_script:
   - psql -U postgres -c "CREATE ROLE fluentd WITH LOGIN ENCRYPTED PASSWORD 'fluentd';"
