add event listeners on process in client

src/Client.ts

@@ -40,10 +40,17 @@ export default class Client extends Eris.Client {
       displayTimestamp: true,
       displayFilename: true,
     });
+    this.events();
     this.loadFunctions();
     this.init();
   }
 
+  private async events() {
+    process.on('unhandledRejection', (error) => {
+      this.signale.error(error);
+    });
+  }
+
   private async loadFunctions() {
     const functions = await fs.readdir('./functions');
     functions.forEach(async (func) => {