Add Users controller
Add integration test for new Users controller
Add helpers test for ApplicationHelper#full_title
Refactor integration tests to use ApplicationHelper#full_title
Correct failure to run due to logic error switching full_title
and have_title.
Refactor tests to use shared example
Add routes for sign up page
Adjust test to use have_selector instead of have_content
Make view pass test
Change stub path for signup to new route