title: Loopback passport reuses last google credentials
body: <p>I have created Loopback app and am using loopback-component-passport to authorize against Google Oauth2. Issue I am having is that when I log in (using login dialog from google) and then logout (using api/Users/logout url and clearing cookies) and then trying to login again, I get authenticated with my last credentials (no google dialog loaded and new access_token is generated). I do not have a chance to type another credentials (unless I open the site in new incognito window or with guest browser user).</p>
  
  <p>I can't find where is something cached so google generates access_token assuming my username. Under what circumstances does google assume what is my username?</p>