added a token object to be read from Discord's token endpoint.

src/Discord.Net.Rest/API/Common/Token.cs

@@ -0,0 +1,19 @@
+#pragma warning disable CS1591
+using Newtonsoft.Json;
+
+namespace Discord.API.Rest
+{
+    internal class Token
+    {
+        [JsonProperty("access_token")]
+        public string AccessToken { get; set; }
+        [JsonProperty("token_type")]
+        public string TokenType { get; set; }
+        [JsonProperty("expires_in")]
+        public int ExpiresIn { get; set; }
+        [JsonProperty("refresh_token")]
+        public string RefreshToken { get; set; }
+        [JsonProperty("scope")]
+        public string Scope { get; set; }
+    }
+}