Establish Travis CI process for Admin-UI

This patch includes the following changes to establish the travis CI process:

1. Add a .travis.yml configuration file for admin-ui project
2. Change some of the rspec test cases' code to fit travis system, the changes
are included in the spec/integration/web/admin_spec.rb & spec/integration/web/user_spec.rb
& spec/integration/cc_spec.rb
3. Adjust selenium-webdriver gem version to 2.39.0 to fit the travis system.

At present, we can use headless solution for the selenium based UI testings in travis CI, after there is an account setup for Admin-UI, we can change to Sauce Lab selenium UI testing to get more better results.