Add request-deferred derivation

pkgs/top-level/emacs-packages.nix

@@ -744,6 +744,33 @@ let self = _self // overrides;
     };
   };
 
+  request-deferred = melpaBuild rec {
+    pname = "request-deferred";
+    version = "0.2.0";
+
+    src = fetchFromGitHub {
+      owner = "tkf";
+      repo = "emacs-request";
+      rev = "adf7de452f9914406bfb693541f1d280093c4efd";
+      sha256 = "0dja4g43zfjbxqvz2cgivgq5sfm6fz1563qgrp4yxknl7bdggb92";
+    };
+
+    packageRequires = [ request deferred ];
+
+    meta = with stdenv.lib; {
+      description = "Easy HTTP request for Emacs Lisp";
+      longDescription = ''
+        Request.el is a HTTP request library with multiple backends. It supports
+        url.el which is shipped with Emacs and curl command line program. User
+        can use curl when s/he has it, as curl is more reliable than url.el.
+        Library author can use request.el to avoid imposing external dependencies
+        such as curl to users while giving richer experience for users who have curl.
+      '';
+      homepage = https://github.com/tkf/emacs-request;
+      license = gpl3Plus;
+    };
+  };
+
   rich-minority = melpaBuild rec {
     pname   = "rich-minority";
     version = "0.1.1";