Add jquery to test_app's application.js

For the :method in link_to elements to work.

Signed-off-by: Joan Tiffany Siy <joan@teamcodeflux.com>
Update test_app home page

Add links for easier navigation

Signed-off-by: Joan Tiffany Siy <joan@teamcodeflux.com>
Update the README with notes about the test app.

Signed-off-by: Joan Tiffany Siy <joan@teamcodeflux.com>