Add TravisCI configuration file

The Chrome installation script comes from the discussion on the TravisCI
issue tracker, "Chromium/Chrome does not work in an OpenVZ container"
(gh-938):

https://github.com/travis-ci/travis-ci/issues/938
Add tests
Add test for updating item
Add tests for task completion
Add test for persistence
Move selectors to declarative JSON file
Automate selector object creation
Create (and use) an "application driver" class