using defined Puma config

This changes threads the `gemstash_env.config` options for Puma through
to the `Puma::CLI.new` call.

Prior to this change `:puma_workers` and `:puma_threads` were ignored
when booting Gemstash via the CLI

lib/gemstash/cli/start.rb

@@ -33,12 +33,24 @@ def puma_config
         File.expand_path("../../puma.rb", __FILE__)
       end
 
+      def store_pidfile
+        gemstash_env.pidfile = pidfile?
+      end
+
+      def pidfile?
+        @cli.options[:pidfile]
+      end
+
       def args
-        config_args + pidfile_args + daemonize_args
+        puma_args + pidfile_args + daemonize_args
       end
 
-      def config_args
-        ["--config", puma_config]
+      def puma_args
+        [
+          '--config', puma_config,
+          '--workers', gemstash_env.config[:puma_workers],
+          '--threads', gemstash_env.config[:puma_threads],
+        ]
       end
 
       def daemonize_args