Isolated API definitions to their own library

src/Discord.Net.Rpc/API/Rpc/AuthenticateResponse.cs

@@ -1,18 +0,0 @@
-#pragma warning disable CS1591
-using Newtonsoft.Json;
-using System;
-
-namespace Discord.API.Rpc
-{
-    public class AuthenticateResponse
-    {
-        [JsonProperty("application")]
-        public Application Application { get; set; }
-        [JsonProperty("expires")]
-        public DateTimeOffset Expires { get; set; }
-        [JsonProperty("user")]
-        public User User { get; set; }
-        [JsonProperty("scopes")]
-        public string[] Scopes { get; set; }
-    }
-}