title: SecurityStamp is not updated on password change
body: <p>I developed an MVC 5 application that uses ASP.NET Identity with custom user store and security stamp.</p>
  <p>The problem is that when I change the password for a user, using this call:</p>
  <pre><code>await store.SetPasswordHashAsync(identity, hashedPassword).ConfigureAwait(true);
  </code></pre>
  <p>the security stamp is not updated.</p>
  <p>The security stamp is only set on user creation. I create users with:</p>
  <pre><code>await userManager.CreateAsync(identity).ConfigureAwait(true);
  </code></pre>
  <p>where <code>identity</code> is the ApplicationUser object.</p>
  <p>How can I solve it?</p>