Check defmethod/defmulti argument matches

[jeluard]

It would be really great to have defmethod checked for arguments accroding to their respective defmulti.

e.g. the following should be reported:

(defmulti some-method (fn [_ s] s))

(defmethod some-method "some-value"
  [_ _ _]
  ..)

Note that the defmethod accepts 3 arguments while the defmulti expects 2.