clean: respect es11

frontend/static/js/api/game/Ball.js

@@ -55,7 +55,7 @@ class Ball
      */
     render(ctx)
     {
-        let distance = this.speed * (this.game.time.deltaTime() / 1000)
+        let distance = this.speed * (this.game.time.deltaTime() / 1000);
 
         this.position.x = this.position.x + distance * Math.cos(this.angle);
         this.position.y = this.position.y - distance * Math.sin(this.angle);
@@ -70,8 +70,8 @@ class Ball
         this.angle = data.angle;
         this.speed = data.speed;
 
-        return this
+        return this;
     }
 }
 
-export { Ball }
+export { Ball };