Commented some tests away
Defined romanize method
Raises ArgumentError if number is zero
Raises ArgumentError if number is negative
Added 'negative?' member method to Integer class
Romanize returns a string "string"
Declared arabic_roman_numbers hash
Initialized arabic_roman_numbers hash
Added member method 'to_a'  Integer class
Duplicates the number argument
Removed duplicaton of number argument

Removed duplication of number argument due to Ruby not natively
supporting it.
Added more keys and values to arabic_roman_numbers
Iteration over arabic_roman_numbers keys
Implemented algorithm
Fixed error by reversing hash temporarily
Removed unneccesary outputs
Removed 'to_a' from Integer class
Removed two characters
Small change in hash to solve error
romanize_spec.rb now running succesful