Passed test: "Booleans should evaluate to themselves."
Passed test: "...and so should integers."
Passed test: "When a call is done to the `quote` form, the argument should be returned without being evaluated."
Passed test: "The `atom` form is used to determine whether an expression is an atom."
Added case for symbols; Passed test: "The `eq` form is used to check whether two expressions are the same atom."
Passed test: "To be able to do anything useful, we need some basic math operators."
Passed test: "The math functions should only allow numbers as arguments."
Ensure integer division