add test for the keys feature
add test for the keys feature

jeremi/couchdbkit,sirex/couchdbkit,sirex/couchdbkit,ghickman/couchdbkit,benoitc/couchdbkit,jeremi/couchdbkit,benoitc/couchdbkit,benoitc/couchdbkit,ghickman/couchdbkit,ghickman/couchdbkit