title: Exclude path from firewall security in symfony4
body: <p>I recently just started with Symfony 4 and having some problems with authentication in the security bundle, security.yaml file.</p>
  
  <p>The security.yaml file has one firewall for the given API routes i want to control:</p>
  
  <pre><code>security:
      providers:
          in_memory:
              memory: ~
  
      firewalls:
          dev:
              pattern: ^/(_(profiler|wdt)|css|images|js)/
              security: false
  
          main:
              pattern: ^/
              anonymous: true
  
      access_control:
          - { path: ^/portal, roles: IS_AUTHENTICATED_ANONYMOUSLY }
          - { path: ^/, roles: ROLE_ADMIN }
  </code></pre>
  
  <p>I would like to restrict all routes from the root level except in this case the /portal route, which should be available for everyone. How am i able to do this.</p>
  
  <p>Currently this gives me a <code>InsufficientAuthenticationException</code> Full <code>authentication is required to access this resource.</code> Exception. Is there something im missing?</p>