create each class and wire them together
buildings can be successfully created

	* also commited my spec list as well
create new apartments, and add method to add an apartment to a building
remove inheritance of classes. there's no need for them.
create a new tenant and calculate the tenant's credit rating
add new tests to add tenant to an apartment
raise error if new tenant has bad credit or if new tenant would crowd apartment
find both credit score and credit rating for an apartment
small refactor of apartment credit_rating method
remove a tenant method is now functioning
display error message if a tenant cannot be found when remove_a_tenant is called
add more test apartments to test file