Added a test case for when every digit is illegible in the account number. Test passed
Added a test case for when every digit of an account number is illegible. There was a connection error during my last commit. It is now acting like the code was already added. The newly added test is test_StringConversionWithAllInvalidDigits. Test passed.
Added a test case where all digits in a number are illegible. Also added documentation for the ConvertToString member function.
Github went down so it may not display all of my changes. I added a test case to test an instance where all digits in an account number are illegible. I also added documentation to my ConvertToString member function.