title: Oauth2 authentication failed
body: <p>I'm trying to use spring OAUTH2sso in my application (client) with an oauth2 provider that have installed. With the client configured in the oauth2 provider and with the clientId, clientSecret, accessTokenUri and userAuthorizationUri configured in the client, when an user are authenticated and authorize the client and after the redirection, the client show me an error of authentication failed because the springOauth2sso library does not get the user details.</p>
  
  <blockquote>
    <p>Whitelabel Error Page This application has no explicit mapping for
    /error, so you are seeing this as a fallback. Thu Jan 21 10:28:28 CET
    2016 There was an unexpected error (type=Unauthorized, status=401).
    Authentication Failed: Could not obtain user details from token</p>
  </blockquote>
  
  <p>I tested my provider with other oauth2 libraries and it was pretty well but I'm not sure about what happened in this case.</p>