Configure Travis CI to use Chrome addon, install ChromeDriver

.travis.yml

@@ -1,11 +1,18 @@
 language: ruby
 addons:
   postgresql: '9.4'
+  chrome: stable
 rvm:
 - 2.3.2
 cache: bundler
 bundler_args: --without development
 before_script:
+- wget -N https://chromedriver.storage.googleapis.com/2.36/chromedriver_linux64.zip -P ~/
+- unzip ~/chromedriver_linux64.zip -d ~/
+- rm ~/chromedriver_linux64.zip
+- sudo mv -f ~/chromedriver /usr/local/share/
+- sudo chmod +x /usr/local/share/chromedriver
+- sudo ln -s /usr/local/share/chromedriver /usr/local/bin/chromedriver
 - for i in config/*.example; do cp "$i" "${i/.example}"; done
 - bundle exec rake db:setup
 script:
@@ -23,4 +30,4 @@ notifications:
   slack:
     secure: 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
     on_failure: always
-    on_success: change
+    on_success: change