feature: Add GuildEmote#CreatorID (#1213)

Co-authored-by: Chris Johnston <chris@thejohnstons.net>

commit 23f5abba48
Author: Christopher Felegy <foxbot@protonmail.com>
Date:   Thu Dec 20 17:10:21 2018 -0500

    lint: clean up some long lines

commit 4a8a809db0
Author: Chris Johnston <chris@thejohnstons.net>
Date:   Sat Dec 15 00:33:05 2018 -0800

    Explain why CreatorId can be null sometimes

commit 9442e4e635
Author: Chris Johnston <chris@thejohnstons.net>
Date:   Fri Dec 14 23:59:01 2018 -0800

    Add the CreatorId property to GuildEmote implementation

commit e0eb94d44c
Author: Chris Johnston <chris@thejohnstons.net>
Date:   Fri Dec 14 23:41:54 2018 -0800

    Update the Emoji API model to add User? attribute

src/Discord.Net.Core/Entities/Emotes/GuildEmote.cs

@@ -30,12 +30,20 @@ namespace Discord
         ///     A read-only list containing snowflake identifiers for roles that are allowed to use this emoji.
         /// </returns>
         public IReadOnlyList<ulong> RoleIds { get; }
+        /// <summary>
+        ///     Gets the user Id that created this emoji.
+        /// </summary>
+        /// <returns>
+        ///     A user Id of the user who created this emoji, which may be null. A null value only indicates that the creator was not supplied as part of the API response.
+        /// </returns>
+        public ulong? CreatorId { get; }
 
-        internal GuildEmote(ulong id, string name, bool animated, bool isManaged, bool requireColons, IReadOnlyList<ulong> roleIds) : base(id, name, animated)
+        internal GuildEmote(ulong id, string name, bool animated, bool isManaged, bool requireColons, IReadOnlyList<ulong> roleIds, ulong? userId) : base(id, name, animated)
         {
             IsManaged = isManaged;
             RequireColons = requireColons;
             RoleIds = roleIds;
+            CreatorId = userId;
         }
 
         private string DebuggerDisplay => $"{Name} ({Id})";

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

@@ -1,4 +1,4 @@
-#pragma warning disable CS1591
+#pragma warning disable CS1591
 using Newtonsoft.Json;
 
 namespace Discord.API
@@ -17,5 +17,7 @@ namespace Discord.API
         public bool RequireColons { get; set; }
         [JsonProperty("managed")]
         public bool Managed { get; set; }
+        [JsonProperty("user")]
+        public Optional<User> User { get; set; }
     }
 }

src/Discord.Net.Rest/Extensions/EntityExtensions.cs

@@ -1,4 +1,4 @@
-using System.Collections.Immutable;
+using System.Collections.Immutable;
 using System.Linq;
 
 namespace Discord.Rest
@@ -6,9 +6,13 @@ namespace Discord.Rest
     internal static class EntityExtensions
     {
         public static GuildEmote ToEntity(this API.Emoji model)
-        {
-            return new GuildEmote(model.Id.Value, model.Name, model.Animated.GetValueOrDefault(), model.Managed, model.RequireColons, ImmutableArray.Create(model.Roles));
-        }
+            => new GuildEmote(model.Id.Value,
+                model.Name,
+                model.Animated.GetValueOrDefault(),
+                model.Managed,
+                model.RequireColons,
+                ImmutableArray.Create(model.Roles),
+                model.User.IsSpecified ? model.User.Value.Id : (ulong?)null);
 
         public static Embed ToEntity(this API.Embed model)
         {