Add version attribute where maintainers |= nckx

This will probably be mandatory soon, and is a step in the right
direction. Removes the deprecated meta.version, and move some meta
sections to the end of the file where I should have put them in
the first place.

pkgs/applications/audio/keyfinder-cli/default.nix

@@ -1,8 +1,8 @@
 { stdenv, fetchFromGitHub, libav, libkeyfinder }:
 
-let version = "2015-09-13"; in
 stdenv.mkDerivation rec {
   name = "keyfinder-cli-${version}";
+  version = "2015-09-13";
 
   src = fetchFromGitHub {
     repo = "keyfinder-cli";
@@ -18,7 +18,6 @@ stdenv.mkDerivation rec {
   enableParallelBuilding = true;
 
   meta = with stdenv.lib; {
-    inherit version;
     inherit (src.meta) homepage;
     description = "Musical key detection for digital audio (command-line tool)";
     longDescription = ''