execute command arguments = 1 string; more intuitive

given that I've been down this road of "why did it explode? oh because it's an array of strings. why is it an array? this should stop" before

franz.tests/Program.cs

@@ -27,7 +27,7 @@ namespace franz.tests
             System.Threading.Thread.Sleep(15000);
             Telefranz.Instance.ProduceMessage(new gray_messages.directorial.execute_command(){ 
                 command= "a!",
-                args= new List<string>(){"param 1", "param 2"}
+                args= "parameters to pass along"
             });
             System.Threading.Thread.Sleep(5000);
             Console.WriteLine("k.");

franz/gray_messages/directorial/execute_command.cs

@@ -15,7 +15,7 @@ namespace gray_messages.directorial
     public class execute_command : gray_messages.message
     {
         public string command { get; set; }
-        public List<string> args { get; set; } = new List<string>();
+        public string args { get; set; }
         public TimeSpan? timeout { get; set; }
     }
 }