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/tools/text/aha/default.nix

@@ -1,8 +1,8 @@
 { stdenv, fetchFromGitHub }:
 
-let version = "0.4.8"; in
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   name = "aha-${version}";
+  version = "0.4.8";
 
   src = fetchFromGitHub {
     sha256 = "1209rda6kc9x88b47y1035zs9lxk0x3qzsb87f8m5b55fdkgxqlj";
@@ -16,7 +16,6 @@ stdenv.mkDerivation {
   enableParallelBuilding = true;
 
   meta = with stdenv.lib; {
-    inherit version;
     description = "ANSI HTML Adapter";
     longDescription = ''
       aha takes ANSI SGR-coloured input and produces W3C-conformant HTML code.