modify gamelayer in createBrick function to make an array. create randomVelocity function for randoming brick's velocity
made some changes to createBricks functon. Added new function called randomWidth and randomHeight for future updates.
add random value algorithm for randomCount method
finish up all random methods. finally implementing random obstacles and speed
clean up code junks
added new method for countdwn, also update method for future uses
complete the countdown label and update method
modify the gamelayer and add option to restart the game after finished