When executing command "deletePerson 0", the error message is, "Index is not a non-zero unsigned integer."
It may not be a very user friendly error, as I think the error is coming from parsing the number into a Index type. Thus, I think a better error message may be like "Sorry, you have input an invalid number! Please try again".

Similar behaviour for deleteLocation.

When executing command "deletePerson 0", the error message is, "Index is not a non-zero unsigned integer."
It may not be a very user friendly error, as I think the error is coming from parsing the number into a Index type. Thus, I think a better error message may be like "Sorry, you have input an invalid number! Please try again".
Similar behaviour for deleteLocation.