treewide: remove wkennington as maintainer

He prefers to contribute to his own nixpkgs fork triton.
Since he is still marked as maintainer in many packages
this leaves the wrong impression he still maintains those.

pkgs/development/compilers/go/1.4.nix

@@ -156,7 +156,7 @@ stdenv.mkDerivation rec {
     homepage = http://golang.org/;
     description = "The Go Programming language";
     license = licenses.bsd3;
-    maintainers = with maintainers; [ cstrahan wkennington ];
+    maintainers = with maintainers; [ cstrahan ];
     platforms = platforms.linux ++ platforms.darwin;
   };
 }

pkgs/development/compilers/go/1.9.nix

@@ -178,7 +178,7 @@ stdenv.mkDerivation rec {
     homepage = http://golang.org/;
     description = "The Go Programming language";
     license = licenses.bsd3;
-    maintainers = with maintainers; [ cstrahan orivej wkennington ];
+    maintainers = with maintainers; [ cstrahan orivej ];
     platforms = platforms.linux ++ platforms.darwin;
   };
 }

pkgs/development/compilers/rust/rustc.nix

@@ -171,7 +171,7 @@ stdenv.mkDerivation {
   meta = with stdenv.lib; {
     homepage = https://www.rust-lang.org/;
     description = "A safe, concurrent, practical language";
-    maintainers = with maintainers; [ madjar cstrahan wizeman globin havvy wkennington ];
+    maintainers = with maintainers; [ madjar cstrahan wizeman globin havvy ];
     license = [ licenses.mit licenses.asl20 ];
     platforms = platforms.linux ++ platforms.darwin;
     broken = broken;