gnu: Add rust-rand-0.7.

* gnu/packages/crates-io.scm (rust-rand-0.7): New variable.
(rust-rand-0.6): Inherit from rust-rand-0.7.

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

gnu/packages/crates-io.scm

@@ -7642,8 +7642,44 @@ to write.")
          (base32
           "1nw0klza45hf127kfyrpxsxd5jw2l6h21qxalil3hkr7bnf7kx7s"))))))
 
+(define-public rust-rand-0.7
+  (package
+    (name "rust-rand")
+    (version "0.7.3")
+    (source
+      (origin
+        (method url-fetch)
+        (uri (crate-uri "rand" version))
+        (file-name (string-append name "-" version ".crate"))
+        (sha256
+         (base32
+          "00sdaimkbz491qgi6qxkv582yivl32m2jd401kzbn94vsiwicsva"))))
+    (build-system cargo-build-system)
+    (arguments
+     `(#:skip-build? #t
+       #:cargo-inputs
+       (("rust-getrandom" ,rust-getrandom-0.1)
+        ("rust-libc" ,rust-libc-0.2)
+        ("rust-log" ,rust-log-0.4)
+        ("rust-packed-simd" ,rust-packed-simd-0.3)
+        ("rust-rand-chacha" ,rust-rand-chacha-0.2)
+        ("rust-rand-core" ,rust-rand-core-0.5)
+        ("rust-rand-hc" ,rust-rand-hc-0.2)
+        ("rust-rand-pcg" ,rust-rand-pcg-0.2))
+       #:cargo-development-inputs
+       (("rust-rand-hc" ,rust-rand-hc-0.2)
+        ("rust-rand-pcg" ,rust-rand-pcg-0.2))))
+    (home-page "https://crates.io/crates/rand")
+    (synopsis "Random number generators and other randomness functionality")
+    (description
+     "Rand provides utilities to generate random numbers, to convert them to
+useful types and distributions, and some randomness-related algorithms.")
+    (license (list license:asl2.0
+                   license:expat))))
+
 (define-public rust-rand-0.6
   (package
+    (inherit rust-rand-0.7)
     (name "rust-rand")
     (version "0.6.5")
     (source
@@ -7654,7 +7690,6 @@ to write.")
         (sha256
          (base32
           "1jl4449jcl4wgmzld6ffwqj5gwxrp8zvx8w573g1z368qg6xlwbd"))))
-    (build-system cargo-build-system)
     (arguments
      `(#:skip-build? #t
        #:cargo-inputs
@@ -7672,14 +7707,7 @@ to write.")
         ("rust-winapi" ,rust-winapi-0.3)
         ("rust-autocfg" ,rust-autocfg-0.1)) ; build-dependency
        #:cargo-development-inputs
-       (("rust-rand-xoshiro" ,rust-rand-xoshiro-0.1))))
+       (("rust-rand-xoshiro" ,rust-rand-xoshiro-0.1))))))
-    (home-page "https://crates.io/crates/rand")
-    (synopsis "Random number generators and other randomness functionality")
-    (description
-     "Rand provides utilities to generate random numbers, to convert them to
-useful types and distributions, and some randomness-related algorithms.")
-    (license (list license:asl2.0
-                   license:expat))))
 
 (define-public rust-rand-0.4
   (package