title: Owin claims - Add multiple ClaimTypes.Role
body: <p>I have an application in which users can be assigned the following roles: </p>
  
  <ul>
  <li>SuperAdmin</li>
  <li>Admin</li>
  <li>User</li>
  </ul>
  
  <p>One user may have assigned two or more roles, eg. both SuperAdmin and User. My application uses claims, and therefore i want to authenticate user roles through claims too. like: </p>
  
  <pre><code>[Authorize(Roles="Admin")]
  </code></pre>
  
  <p>Unfortunately, i dont know how i can add multiple roles to my ClaimTypes.Role. I have the following code:</p>
  
  <pre><code>var identity = new ClaimsIdentity(new[] {
                  new Claim(ClaimTypes.Name, name),
                  new Claim(ClaimTypes.Email, email),
                  new Claim(ClaimTypes.Role, "User", "Admin", "SuperAdmin")
          },
              "ApplicationCookie");
  </code></pre>
  
  <p>As you can see, i tried to add more roles for the sake of illustrating, but obviously its done in a wrong way, and therefore doesn't work. 
  Any help is therefore much appreciated.</p>