jAustin hw5 submission

Similar to the classwork today I found that a VAST number of tests can be written just for validation. I recreated the tenant / apartment / building classes with TDD, but did not get to validations because they would have had to have been extensive (and time consuming). I did not write the appt_by_cred function that was in my original building class as I got tired and was having trouble writing suitable spec code.