Bullets shooted doesn't appear

[Pombo]

I made a game to test what I learned, with a blue tank that is the player, it has a cannon and shoots when you press "1", and a red tank that follows you. The problem is that the bullet that the player shoots does not appear. I checked the entire code and didn't find what was wrong.
I'll leave here the .zip file with the entire game. The code that makes the bullet work is only in the files main.lua, player.lua, bullet.lua and canhao.lua. I put comments by the codes explaining some functions.

[CogentInvalid]

In Bullet:draw() you're calling love.graphics.newImage. Instead you should call love.graphics.draw.