Update wallaby config for default browser size

[andrewconnell]

Expected Behavior

If all tests pass in the console with npm run test, they should also pass when using WallabyJS.

Actual Behavior

One test fails in Wallaby... the breadcrumb has a single test that fails (two except statements fail). The issue is related to the default size of the test browser in Wallaby (800x600). The wallaby config needs to default to a smaller size.

REF: https://github.com/wallabyjs/public/issues/915#issuecomment-268819018

Steps to Reproduce Behavior

• Run the tests in the console (npm run test).
• Run the tests in Wallaby (within VSCode for instance).

Observe that the breadcrumb has a single test that fails (two except statements fail).