title: Import yml config in symfony2 config.yml file
body: <p>In my Symfony2 config.yml file, I'd like to import some configs that I'd prefer gather in a separate yml file.</p>
  
  <p>I used:</p>
  
  <pre><code>imports:
  - { resource: parameters.yml }
  - { resource: sso_accounts.yml }
  </code></pre>
  
  <p>And in my sso_accounts.yml file I basically have:</p>
  
  <pre><code>sso_accounts:
    company:
      publickey:  publickey
      secret:     privatekey
      users:      [ user1@email.com, user2@email.com ]
  </code></pre>
  
  <p>But (there's always a but...) I got this error:</p>
  
  <pre><code>Whoops, looks like something went wrong.
  
  2/2 FileLoaderLoadException: Cannot import resource "/Users/mycomp/Sites/myapp/app/config/sso_accounts.yml" from "/Users/mycomp/Sites/myapp/app/config/config.yml".
  
  1/2 InvalidArgumentException: There is no extension able to load the configuration for "sso_accounts" (in /Users/mycomp/Sites/myapp/app/config/sso_accounts.yml). Looked for namespace "sso_accounts", found "framework", "security", "twig", "monolog", "swiftmailer", "doctrine", "assetic", "sensio_framework_extra", "jms_security_extra", "problematic_acl_manager", "twig_js", "fos_js_routing"
  </code></pre>
  
  <p>What's wrong with my import?</p>