Bump the sleep value up to allow installers to complete

Author: rbackhouse

.travis.yml

@@ -6,5 +6,5 @@ before_install:
 before_script:
  - npm install
  - node server/server.js &
- - sleep 3
-script: node ./server/phantom-server.js
+ - sleep 20
+script: node ./server/phantom-server.js