Issue integrating with fastboot

When using ember-cognito with fastboot, page refreshing logs the user out.

After refreshing, I get an error : `The authenticator "authenticator:cognito" rejected to restore the session - invalidating…`. This doesn't occur when fastboot is disabled. I'm using a `CookieStore` as described in the `ember-simple-auth` docs as well as a `current-user` service as described in docs here.