emacs-packages: Drop manually created nyan-mode derivation

Use autogenerated modules from melpa instead

pkgs/applications/editors/emacs-modes/nyan-mode/default.nix

@@ -1,30 +0,0 @@
-{lib, trivialBuild, fetchFromGitHub}:
-
-trivialBuild rec {
-  pname    = "nyan-mode";
-  version  = "20150128";
-
-  src = fetchFromGitHub {
-    owner  = "TeMPOraL";
-    repo   = pname;
-    rev    = "41faa2c809da7b2cb3e6f8fadefae3f338ced3f2";
-    sha256 = "1idaac7sjc8hhbf5zif61ncg1pvg28c0qfihavdx61albww0ll7f";
-  };
-
-  patches = [ ./directory.patch ];
-
-  preBuild = ''
-    substituteInPlace nyan-mode.el \
-      --replace "@OUT@" "$out/"
-  '';
-
-  postInstall = ''
-    cp -r img $out
-    cp -r mus $out
-  '';
-
-  meta = {
-    description = "An analog indicator of the position in the buffer";
-    license = lib.licenses.gpl3Plus;
-  };
-}

pkgs/applications/editors/emacs-modes/nyan-mode/directory.patch

@@ -1,13 +0,0 @@
-diff --git a/nyan-mode.el b/nyan-mode.el
-index 939a25a..3d0b983 100644
---- a/nyan-mode.el
-+++ b/nyan-mode.el
-@@ -106,7 +106,7 @@ This can be t or nil."
-   :group 'nyan)
- 
- 
--(defconst +nyan-directory+ (file-name-directory (or load-file-name buffer-file-name)))
-+(defconst +nyan-directory+ "@OUT@")
- 
- (defconst +nyan-cat-size+ 3)
- 

pkgs/top-level/emacs-packages.nix

@@ -380,10 +380,6 @@ let
       };
     };
 
-    nyan-mode = callPackage ../applications/editors/emacs-modes/nyan-mode {
-      inherit lib;
-    };
-
     org-mac-link =
       callPackage ../applications/editors/emacs-modes/org-mac-link { };