update selenium before start

Author: Bogdan Livadariu

.travis.yml

@@ -12,5 +12,6 @@ install:
 before_script:
   - npm install -g grunt-cli
 script:
+  - node_modules/grunt-protractor-runner/node_modules/.bin/webdriver-manager update
   - node_modules/grunt-protractor-runner/node_modules/.bin/webdriver-manager start &
   - npm test