gnu: Add rust-quickcheck-0.4.

* gnu/packages/crates-io.scm (rust-quickcheck-0.4): New variable.
(rust-quickcheck-0.2): Inherit from rust-quickcheck-0.4.

Signed-off-by: Efraim Flashner <efraim@flashner.co.il>

gnu/packages/crates-io.scm

@@ -11861,9 +11861,29 @@ integers, floats, tuples, booleans, lists, strings, options and results.")
         ("rust-log" ,rust-log-0.3)
         ("rust-rand" ,rust-rand-0.3))))))
 
+(define-public rust-quickcheck-0.4
+  (package
+    (inherit rust-quickcheck-0.5)
+    (name "rust-quickcheck")
+    (version "0.4.1")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (crate-uri "quickcheck" version))
+       (file-name
+        (string-append name "-" version ".tar.gz"))
+       (sha256
+        (base32
+         "01hligcv1h4pvc8ykch65qjzi7jgcq2s462v69j27slc84fl3hh2"))))
+    (arguments
+     `(#:cargo-inputs
+       (("rust-env-logger" ,rust-env-logger-0.3)
+        ("rust-log" ,rust-log-0.3)
+        ("rust-rand" ,rust-rand-0.3))))))
+
 (define-public rust-quickcheck-0.2
   (package
-    (inherit rust-quickcheck-0.9)
+    (inherit rust-quickcheck-0.4)
     (name "rust-quickcheck")
     (version "0.2.27")
     (source
@@ -11873,12 +11893,7 @@ integers, floats, tuples, booleans, lists, strings, options and results.")
        (file-name (string-append name "-" version ".tar.gz"))
        (sha256
         (base32
-         "1vb4acppaavlnchzc1jmn5wlkgir9x9gmhgp97bavyxxqxgsg1nh"))))
+         "1vb4acppaavlnchzc1jmn5wlkgir9x9gmhgp97bavyxxqxgsg1nh"))))))
-    (arguments
-     `(#:cargo-inputs
-       (("rust-env-logger" ,rust-env-logger-0.3)
-        ("rust-log" ,rust-log-0.3)
-        ("rust-rand" ,rust-rand-0.3))))))
 
 (define-public rust-quickcheck-macros-0.8
   (package