Solution seems to be broken

[pbortnick]

The solution returns an error:
1) Rock Dodger endGame() removes the "keydown" event listener: Error: spy was never called with [ 'keydown', [Function: moveDodger] ] at assert (node_modules/expect/lib/assert.js:29:9) at Expectation.toHaveBeenCalledWith (node_modules/expect/lib/Expectation.js:333:28) at Context.it (test/index-test.js:173:19)

[pbortnick]

Change
document.removeEventListener('keydown', moveDodger)
to:
window.removeEventListener('keydown', moveDodger)
in endGame()