Update IMessage.cs

src/Discord.Net.Core/Entities/Messages/IMessage.cs

@@ -3,7 +3,7 @@ using System.Collections.Generic;
 
 namespace Discord
 {
-    public interface IMessage : ISnowflakeEntity
+    public interface IMessage : ISnowflakeEntity, IDeletable
     {
         /// <summary> Gets the type of this system message. </summary>
         MessageType Type { get; }
@@ -40,4 +40,4 @@ namespace Discord
         /// <summary> Returns the ids of users mentioned in this message. </summary>
         IReadOnlyCollection<ulong> MentionedUserIds { get; }
     }
-}
+}