This is a simple quick Test Driven Development Excercise.

I have provided for you two classes, BowlingGame and it's corresponding BowlingGameTest

For the purpose of this example the tests here should be considered an acceptance test suite.

Setup: 
clone into the local machine
run php composer.phar install --dev
vendor/bin/phpunit from the root directory

Bowling:
Each game consists of 10 frames.
Each frame a bowler has 2 chances to knock down all of the pins(10).
If the bowler is unable to knock down all pins his score for the frame is the sum of the pins he knocked down
If the bowler is able to knock down all pins in both rolls, it is considered a spare. His score is 10 plus the next roll.
If the bowler is able to knock down all pins in one roll, it is a Strike.  His score is 10 plus the score of the next two rolls.
The tenth frame is a special frame. If the bowler is able to roll a spare, he also gets an additional roll.  If the bowler gets a strike, he gets two additional rolls.
Score of the game is the total of all frames.

More info on bowling scoring here: http://en.wikipedia.org/wiki/Ten-pin_bowling

The goal of this excercise is to use Test Driven Development to pass all of the acceptance tests provided for you.

RULES:
Every line of code should be written after a new test.
The interface of BowlingGame cannot be changed.
The acceptance tests cannot be changed.