User should be able to sign up.
User should be able to log in with new account.
User should be able to click on "new game," button and start a new game.
User should be able to start as, 'X,' and switch between it and O throughout the game.
User should be able to start a new game once board is full.
User should be able to log out of account if they choose.
User should NOT be able to access game once signed out.
User should be able to log back in once logged out.