gnu: Add rust-antidote.

* gnu/packages/crates-io.scm (rust-antidote): New variable.

gnu/packages/crates-io.scm

@@ -28,6 +28,27 @@
 ;;; Please: Try to add new module packages in alphabetic order.
 ;;;
 
+(define-public rust-antidote
+  (package
+    (name "rust-antidote")
+    (version "1.0.0")
+    (source
+      (origin
+        (method url-fetch)
+        (uri (crate-uri "antidote" version))
+        (file-name (string-append name "-" version ".tar.gz"))
+        (sha256
+         (base32
+          "19g2sw2qa2ibnh4x7j1snk46593jgx6y7rnvva496ynq61af5z9l"))))
+    (build-system cargo-build-system)
+    (home-page "https://github.com/sfackler/rust-antidote")
+    (synopsis "Poison-free Mutex and RwLock types")
+    (description
+    "These types expose identical APIs to the standard library @code{Mutex} and
+@code{RwLock} except that they do not return @code{PoisonError}s.")
+    (license (list license:asl2.0
+                   license:expat))))
+
 (define-public rust-autocfg
   (package
     (name "rust-autocfg")