gnu: Add julia-json.

* gnu/packages/julia-xyz.scm (julia-json-0.21.0): New variable.

gnu/packages/julia-xyz.scm

@@ -227,3 +227,23 @@ tools to build binary dependencies for Julia packages.")
     (description "@code{Parsers} is a collection of type parsers and utilities
 for Julia")
     (license license:expat)))
+
+(define-public julia-json
+  (package
+    (name "julia-json")
+    (version "0.21.0")
+    (source
+     (origin
+       (method git-fetch)
+       (uri (git-reference
+             (url "https://github.com/JuliaIO/JSON.jl")
+             (commit (string-append "v" version))))
+       (file-name "JSON")
+       (sha256
+        (base32 "0knmfjhchd3ggy86dsfyb7l4v3fv5dcr207cgp54mj7rj96caqsm"))))
+    (propagated-inputs `(("julia-parsers" ,julia-parsers)))
+    (build-system julia-build-system)
+    (home-page "https://github.com/JuliaIO/JSON.jl")
+    (synopsis "JSON parsing and printing")
+    (description "Parsing and printing JSON in pure Julia.")
+    (license license:expat)))