Add LcdNum class and spec
Refactor specs, reform directory structure, create LcdNumSet class and spec
add .valid_hash and #initialize methods and spec for LcdNumSet
complete the LcdNumSet class and spec
Rename LcdNumSet to LcdNumRow
Add add LcdNumRow.to_hash
Add LcdNumFile class and spec
Use LcdNumFile as standard, remove prototype AccountNumberInterpreter