doing: modernize

pkgs/by-name/do/doing/package.nix

@@ -1,20 +1,18 @@
 {
   lib,
-  bundlerEnv,
-  ruby,
+  bundlerApp,
   bundlerUpdateScript,
 }:
 
-bundlerEnv {
+bundlerApp {
   pname = "doing";
-  version = (import ./gemset.nix).doing.version;
+  exes = lib.singleton "doing";
 
-  inherit ruby;
   gemdir = ./.;
 
   passthru.updateScript = bundlerUpdateScript "doing";
 
-  meta = with lib; {
+  meta = {
     description = "Command line tool for keeping track of what you’re doing and tracking what you’ve done";
     longDescription = ''
       doing is a basic CLI for adding and listing "what was I doing" reminders
@@ -22,12 +20,12 @@ bundlerEnv {
       sections/categories and flexible output formatting.
     '';
     homepage = "https://brettterpstra.com/projects/doing/";
-    license = licenses.mit;
-    maintainers = with maintainers; [
+    license = lib.licenses.mit;
+    maintainers = with lib.maintainers; [
       ktf
       nicknovitski
     ];
-    platforms = platforms.unix;
+    platforms = lib.platforms.unix;
     mainProgram = "doing";
   };
 }