nano: 2.8.7 -> 2.9.0

See https://lists.gnu.org/archive/html/info-gnu/2017-11/msg00006.html
for release information

pkgs/applications/editors/nano/default.nix

@@ -20,11 +20,11 @@ let
 
 in stdenv.mkDerivation rec {
   name = "nano-${version}";
-  version = "2.8.7";
+  version = "2.9.0";
 
   src = fetchurl {
     url = "mirror://gnu/nano/${name}.tar.xz";
-    sha256 = "0nhns59smd43mad2w6lnaxqnj4h6ifnlivi6cwydg646jm31gqzv";
+    sha256 = "17hjgvig59a2ha2b0494bprrci3d33sayjqvxjhsnlzgr8whrlyj";
   };
 
   nativeBuildInputs = [ texinfo ] ++ optional enableNls gettext;