Ex5.6 - 1 - h1 selector
Ex5.6 - 2 - RSpec shared examples
Ex5.6 - 3 - link tests
Ex5.6 - 4 - test (and re-use in tests) full_title helper
Add Users with validation - 6.2 done
Add password_digest - 6.3.1 done
Add password - 6.3.4 done
Ex6.5 - 1 - test email case
Ex6.5 - 2 - email in-place downcase
Ex6.5 - 3 - ".." is invalid in email