Fix an issue during checking whether the tank reaches the boundary
Code Refactor. Let tank handle move by itself.
Finish the basic function to make tank fire, have bugs!
Code Refactor. Make Tank to create the position by itself
Code Refactor. Move IsCrash to tank
Fix some build errors
Fix an issue that we calculate the wrong position of missile
Code Refactor. Add speed for tank
Add client side configuration
Remove the missile if it is not on the screen
Fire with sound
Code Refactor. Rename the clientconfig.js to config.js
Fix an typo error.
Code Refactor. Move some magic number to config.js.
Check the collision when the tank moves to left.
Remove the magic number.
Fix a defect that will move too much during move to the lest.
Finish the basic function to do the right collision check.
Fix the defect of moving to the left and right.

I didn't take the y coordinate when I implement move to left or right.
Finish the basic function to move up / down.