update chromedriver
diff --git a/.travis.yml b/.travis.yml
index 21c6fe6..b690766 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -29,7 +29,7 @@
   - sh -e /etc/init.d/xvfb start
 
 before_script:
-  - wget http://chromedriver.storage.googleapis.com/2.35/chromedriver_linux64.zip
+  - wget http://chromedriver.storage.googleapis.com/2.40/chromedriver_linux64.zip
   - unzip chromedriver_linux64.zip
   - export PATH=$PATH:$PWD
   - ./tool/travis-setup.sh