Add BulkMessageDelete Functionality

src/Discord.Net.Net45/Discord.Net.csproj

@@ -241,6 +241,9 @@
     <Compile Include="..\Discord.Net\API\Client\Rest\AddGuildBan.cs">
       <Link>API\Client\Rest\AddGuildBan.cs</Link>
     </Compile>
+    <Compile Include="..\Discord.Net\API\Client\Rest\BulkMessageDelete.cs">
+      <Link>API\Client\Rest\BulkMessageDelete.cs</Link>
+    </Compile>
     <Compile Include="..\Discord.Net\API\Client\Rest\CreateChannel.cs">
       <Link>API\Client\Rest\CreateChannel.cs</Link>
     </Compile>

src/Discord.Net/API/Client/Rest/BulkMessageDelete.cs

@@ -0,0 +1,23 @@
+using Newtonsoft.Json;
+ 
+ namespace Discord.API.Client.Rest
+ {
+     [JsonObject(MemberSerialization.OptIn)]
+     public class BulkMessageDelete : IRestRequest
+     {
+         string IRestRequest.Endpoint => $"/channels/{ChannelId}/messages/bulk_delete";
+         string IRestRequest.Method => "POST";
+         object IRestRequest.Payload => this;
+ 
+         public ulong ChannelId { get; set; }
+ 
+         public BulkMessageDelete(ulong channelId, ulong[] messageIds)
+         {
+             ChannelId = channelId;
+             MessageIds = messageIds;
+         }
+ 
+         [JsonProperty("messages")]
+         public ulong[] MessageIds { get; set; }
+     }
+ }

src/Discord.Net/Models/Channel.cs

@@ -200,6 +200,13 @@ namespace Discord
             }
         }
 
+        public async Task DeleteMessages(Message[] messages) => await DeleteMessages(messages.Select(m => m.Id).ToArray());
+
+        public async Task DeleteMessages(ulong[] messageIds)
+        {
+            await Client.ClientAPI.Send(new BulkMessageDelete(Id, messageIds));
+        }
+
         public async Task Delete()
         {
             try { await Client.ClientAPI.Send(new DeleteChannelRequest(Id)).ConfigureAwait(false); }