--
After the upgrade to use voluptuous to parse the configuration, sensor.imap needs to pass username instead user. Note that user also works, but to keep it coherent, we are updating the documentation.

(home_assistant) ↪ hass --script check_config
Testing configuration at /home/hass/.homeassistant
16-08-28 00:49:35 ERROR (MainThread) [homeassistant.bootstrap] Invalid config for [sensor.imap]: required key not provided @ data['username']. Got None
Failed config
  sensor.imap:
    user: <redacted>
    port: 993
    platform: imap
    password: <redacted>
    server: imap.gmail.com
    name: Gmail Alerts

Successful config (partial)
  sensor.imap:

   After replacing ```user``` by ```username```, ```hass --script check_config``` works as expected.