Make it clear no access token is needed for mocked-Launch spec tests

[perlmonger42]

The dummy token used in the specs does not need to be replaced with a real token, because the unit tests don't actually hit a Launch server. I've changed

const accessToken = 'Dummy-Access-Token';

to

const accessToken = 'No real token needed here because Launch calls are mocked';

in an attempt to make that clearer.