Add code and tests for 'yyyy_mm_dd_hh_mm'
Add code and tests for 'yyyy_mm_dd_hh_mm_ss'
Add tests and code for 'zipcode'
Add tests and code for 'email_address'
Refactor smaller date checkers to use 'yyyy_mm_dd_hh_mm_ss'
Add tests and code for 'yyyy_mm_dd'
Add tests and code for 'mm_dd_yyyy'
Add tests and code for 'yyyy'
Add tests and code for 'hh_mm'
Add tests and code for 'hh_mm_ss'
Add tests and code for 'matches_regex'