delete-by-kind deletes too many things

[trptcolin]

Doing the following gives me unexpected results:

(save {:kind "user" :name "Colin"})
(println "before:" (count (find-by-kind "user")))
(delete-by-kind "foobar")
(println "after:" (count (find-by-kind "user")))

;; output:
; before: 1
; after: 0

This is when using (with-in-memory-datastore) in a spec (via speclj). This definitely does not affect the Mongo datastore (verified in a repl); not sure about other datastores.