Update exclusion

Because excluded keys are simply removed from all hashes, be_json_eql is not testing for their presence. Keys are excluded because we can't guarantee the value will match (id, created_at, updated_at). By removing them we avoid the conflicting values but we lose the check for presence. I solved this by instead setting the value of excluded keys to 1. This way we no longer care about conflicting values and retain the presence check.