Add time methods to Audit Log entries (#1443)

* aaaaa

* Update GuildAuditLogs.js

src/structures/GuildAuditLogs.js

@@ -1,4 +1,5 @@
 const Collection = require('../util/Collection');
+const Snowflake = require('../util/Snowflake');
 
 const Targets = {
   GUILD: 'GUILD',
@@ -226,6 +227,24 @@ class GuildAuditLogsEntry {
       this.target = guild[`${targetType.toLowerCase()}s`].get(data.target_id);
     }
   }
+
+  /**
+   * The timestamp this entry was created at
+   * @type {number}
+   * @readonly
+   */
+  get createdTimestamp() {
+    return Snowflake.deconstruct(this.id).timestamp;
+  }
+
+  /**
+   * The time this entry was created
+   * @type {Date}
+   * @readonly
+   */
+  get createdAt() {
+    return new Date(this.createdTimestamp);
+  }
 }
 
 GuildAuditLogs.Actions = Actions;