Fix Untitled Goose Game test

[pauln]

The Untitled Goose Game test had an incorrect "size" specified, which resulted in the following error (which also prevented subsequent tests from running):

UnhandledPromiseRejectionWarning: Error: Evaluation failed: TypeError: Cannot read property 'w' of undefined
    at parseOverlays (file:///home/paul/src/SierraDeathGenerator/js/scripts.js:584:14)

Now that the test runs, it does seem to be picking up a difference; the character width and/or offset seems to be slightly different from when the expected test output was generated.