title: Refresh access_token via refresh_token in Keycloak
body: <p>I need to make the user keep login in the system if the user's <code>access_token</code> get expired and user want to keep login. How can I get newly updated <code>access_token</code> with the use of <code>refresh_token</code> on <a href="https://www.keycloak.org" rel="noreferrer">Keycloak</a>?</p>
  
  <p>I am using <a href="https://github.com/vert-x3/vertx-auth" rel="noreferrer">vertx-auth</a> for the auth implementation with <a href="https://www.keycloak.org" rel="noreferrer">Keycloak</a> on <a href="http://vertx.io" rel="noreferrer">vert.x</a>. Is it possible to refresh <code>access_token</code> with <a href="https://github.com/vert-x3/vertx-auth" rel="noreferrer">vertx-auth</a> or <a href="https://www.keycloak.org" rel="noreferrer">Keycloak</a>'s REST API itself? Or what will be another implementation of this?</p>