Added scripts: test for running tests with npm test.
Added scripts: test for running tests with npm test.

kevinnorris/arcade-mode,freeCodeCamp/arcade-mode,freeCodeCamp/arcade-mode,kevinnorris/arcade-mode,kevinnorris/arcade-mode,kevinnorris/arcade-mode,freeCodeCamp/arcade-mode,freeCodeCamp/arcade-mode