Stub authentication server used by ember-simple-auth during development

I'm using ember-simple-auth in my emberjs app to authenticate via oauth2-password-grant with my own (currently unimplemented) service.

I'd like to continue developing the front-end before creating the authentication service.

Can the authentication service be stubbed so login/logout features can be used? I'm aware that I mock it with http-mock during tests, but I would also like to work on the front-end design and view it in the browser.