Downgrade selenium to version 3.1

.travis.yml

@@ -45,13 +45,13 @@ before_install:
   - sudo mv chromedriver /usr/bin
   - sudo chmod +x /usr/bin/chromedriver
   # Get Selenium
-  - wget http://selenium-release.storage.googleapis.com/3.8/selenium-server-standalone-3.8.0.jar
+  - wget http://selenium-release.storage.googleapis.com/3.1/selenium-server-standalone-3.1.0.jar
   # Check java
   - java -version
   - sudo apt-get install oracle-java8-installer
   - java -version
   #- java -jar selenium-server-standalone-3.7.1.jar -log selenium.log > /dev/null &
-  - java -jar selenium-server-standalone-3.8.0.jar -log selenium.log  > /dev/null &
+  - java -jar selenium-server-standalone-3.1.0.jar -log selenium.log  > /dev/null &
   - nohup bash -c "webdriver-manager start 2>&1 &"
   - sleep 10