update to 4.4.0
    add ErrorHandler, HttpClient, Mailer and Mime components
    use range dependencies
    drop dependency on fig/link-util
    raise dependency on doctrine/annotations 1.7
    raise dependency on doctrine/doctrine-bundle 1.5
    raise dependency on egulias/email-validator 2.1.10
    raise dependency on monolog/monolog 1.25.1
    raise dependency on symfony/contracts 1.1.8
    raise dependency on symfony/polyfill 1.11
    allow twig 3 (review #1774967)
    allow doctrine-bundle 2 (review #1775102)
    add dependency on guzzlehttp/promises
    add dependency on masterminds/html5
    add dependency on mongodb/mongodb
    add dependency on nyholm/psr7
    add dependency on psr/http-client
    add dependency on sodium extension