Testing

[aberry22]

Basic tests:

User input validation: Check for correct user input when adding expenses. -Must enter non-zero number for expense -Must add a valid name for expense - no repeating names(maybe)

Logic verification: -Run various features with simple inputs and verify that the math calculations are working as intended -No division by zero -Make sure all numbers are doubles to avoid floating point errors

Find and fix any runtime errors

[Macaela-Morrison]

This looks good. We can add and document more tests here as needed