lolcat: use bundlerApp, fix audit warning

pkgs/tools/misc/lolcat/Gemfile

···
-source "http://rubygems.org"
-gem "lolcat"
+source "https://rubygems.org"
+gem "lolcat"

pkgs/tools/misc/lolcat/Gemfile.lock

···
 GEM
-  remote: http://rubygems.org/
+  remote: https://rubygems.org/
   specs:
     lolcat (99.9.69)
       manpages (~> 0.6.1)
···
   lolcat
 
 BUNDLED WITH
-   1.16.3
+   1.17.2

pkgs/tools/misc/lolcat/default.nix

···
-{ lib, bundlerEnv, ruby }:
+{ lib, bundlerApp }:
 
-bundlerEnv rec {
-  name = "${pname}-${version}";
+bundlerApp {
   pname = "lolcat";
-  version = (import ./gemset.nix).lolcat.version;
-
-  inherit ruby;
-
-  # expects Gemfile, Gemfile.lock and gemset.nix in the same directory
   gemdir = ./.;
+  exes = [ "lolcat" ];
 
   meta = with lib; {
     description = "A rainbow version of cat";
     homepage    = https://github.com/busyloop/lolcat;
     license     = licenses.bsd3;
-    maintainers = with maintainers; [ StillerHarpo ];
+    maintainers = with maintainers; [ StillerHarpo manveru ];
   };
 }

pkgs/tools/misc/lolcat/gemset.nix

···
 {
   lolcat = {
     dependencies = ["manpages" "optimist" "paint"];
+    groups = ["default"];
+    platforms = [];
     source = {
-      remotes = ["http://rubygems.org"];
+      remotes = ["https://rubygems.org"];
       sha256 = "0d1yh2ikyhyh7am4qznd6fzv2pyvk82xrnsrsbbyxzcqfz9x6aa9";
       type = "gem";
     };
     version = "99.9.69";
   };
   manpages = {
+    groups = ["default"];
+    platforms = [];
     source = {
-      remotes = ["http://rubygems.org"];
+      remotes = ["https://rubygems.org"];
       sha256 = "11p6ilnfda6af15ks3xiz2pr0hkvdvadnk1xm4ahqlf84dld3fnd";
       type = "gem";
     };
     version = "0.6.1";
   };
   optimist = {
+    groups = ["default"];
+    platforms = [];
     source = {
-      remotes = ["http://rubygems.org"];
+      remotes = ["https://rubygems.org"];
       sha256 = "05jxrp3nbn5iilc1k7ir90mfnwc5abc9h78s5rpm3qafwqxvcj4j";
       type = "gem";
     };
     version = "3.0.0";
   };
   paint = {
+    groups = ["default"];
+    platforms = [];
     source = {
-      remotes = ["http://rubygems.org"];
+      remotes = ["https://rubygems.org"];
       sha256 = "0ldb269l3pzkihmsws19cr9h3l6naw8c2fqpav8ck3nllnyiv7r2";
       type = "gem";
     };