Support for 1
Improve error message.
Support for 0.
Support for 2
Failing test for III.
Fixed bug in test
Fix bug in impl :)
Support for 3.
Failing test for 4.
Added support for 4
Added a smarter test for single digits
Fix bug in test.
Support for digits <10.
Failing test for 10.
Added support for 10
Added failing test for 11 throiugh 19
Support to 19, inclusive.
Failing test for 100.
Added support for hundreds
Removed comments