Changes for clojure.core/associative?

Clinton on Fri, 20 Jan 2012
user=> (associative? [1 2 3]) ; vector
true
user=> (associative? '(1 2 3)) ; list
false
user=> (associative? {:a 1 :b 2}) ; map
true
user=> (associative? #{:a :b :c}) ; set
false
user=> (associative? "fred") ; string
false