Support zero-interaction logins via config

[jdek]

Currently when using localauth0 to mock the auth0 service, there is a login page served which requires a manual click from the user. For use in automated tests, and other similar scenarios, it would be beneficial to automatically login without any client-side interaction.

I believe it's possible to do this already by specifying bypass=1 as a query parameter but this requires modifying usage on the client application which is not always possible (especially in the case of prepackaged Auth0 libraries).

Adding a global configuration option to enable the bypass functionality seems like a reasonable way to support this.