feat(Guild): add includeApplications option for fetchIntegrations (#4762)

src/structures/IntegrationApplication.js

@@ -0,0 +1,25 @@
+'use strict';
+
+const Application = require('./interfaces/Application');
+
+/**
+ * Represents an Integration's OAuth2 Application.
+ * @extends {Application}
+ */
+class IntegrationApplication extends Application {
+  _patch(data) {
+    super._patch(data);
+
+    if (typeof data.bot !== 'undefined') {
+      /**
+       * The bot {@link User user} for this application
+       * @type {?User}
+       */
+      this.bot = this.client.users.add(data.bot);
+    } else if (!this.bot) {
+      this.bot = null;
+    }
+  }
+}
+
+module.exports = IntegrationApplication;