我克隆了回购，检查了v2.1.3并运行composer install。这一切看起来都不错，最后我收到了这些通知：
symfony/intl suggests installing ext-intl (to use the component with locales other than "en")
symfony/form suggests installing symfony/framework-bundle (For templating with PHP.)
symfony/security-core suggests installing symfony/expression-language (For using the expression voter)
symfony/security-core suggests installing ircmaxell/password-compat (For using the BCrypt password encoder in PHP <5.5)
symfony/twig-bridge suggests installing symfony/templating (For using the TwigEngine)
symfony/twig-bridge suggests installing symfony/security (For using the SecurityExtension)
symfony/twig-bridge suggests installing symfony/expression-language (For using the ExpressionExtension)
symfony/validator suggests installing egulias/email-validator (Strict (RFC compliant) email validation)
symfony/validator suggests installing symfony/expression-language (For using the 2.4 Expression validator)
symfony/var-dumper suggests installing ext-symfony_debug ()
m6web/symfony2-coding-standard suggests installing m6web/coke (PHP CodeSniffer configurator)
symfony/dependency-injection suggests installing symfony/proxy-manager-bridge (Generate service proxies to lazy load them)
symfony/http-kernel suggests installing symfony/class-loader ()
symfony/routing suggests installing symfony/expression-language (For using expression matching)
rossriley/flysystem53 suggests installing predis/predis (Allows you to use Predis for caching)
rossriley/flysystem53 suggests installing league/flysystem-eventable-filesystem (Allows you to use EventableFilesystem)
rossriley/flysystem53 suggests installing league/flysystem-rackspace (Allows you to use Rackspace Cloud Files)
rossriley/flysystem53 suggests installing league/flysystem-copy (Allows you to use Copy.com storage)
rossriley/flysystem53 suggests installing league/flysystem-azure (Allows you to use Windows Azure Blob storage)
rossriley/flysystem53 suggests installing league/flysystem-webdav (Allows you to use WebDAV storage)
rossriley/flysystem53 suggests installing league/flysystem-aws-s3-v2 (Use S3 storage with AWS SDK v2)
rossriley/flysystem53 suggests installing league/flysystem-aws-s3-v3 (Use S3 storage with AWS SDK v3)
rossriley/flysystem53 suggests installing league/flysystem-dropbox (Use Dropbox storage)
rossriley/flysystem53 suggests installing league/flysystem-cached-adapter (Flysystem adapter decorator for metadata caching)
rossriley/flysystem53 suggests installing league/flysystem-sftp (Allows SFTP server storage via phpseclib)
rossriley/flysystem53 suggests installing league/flysystem-ziparchive (Allows you to use ZipArchive adapter)
siriusphp/upload suggests installing knplabs/gaufrette (Alternative filesystem abstraction library for upload destinations)
monolog/monolog suggests installing graylog2/gelf-php (Allow sending log messages to a GrayLog2 server)
monolog/monolog suggests installing raven/raven (Allow sending log messages to a Sentry server)
monolog/monolog suggests installing doctrine/couchdb (Allow sending log messages to a CouchDB server)
monolog/monolog suggests installing ruflin/elastica (Allow sending log messages to an Elastic Search server)
monolog/monolog suggests installing videlalvaro/php-amqplib (Allow sending log messages to an AMQP server using php-amqplib)
monolog/monolog suggests installing ext-amqp (Allow sending log messages to an AMQP server (1.0+ required))
monolog/monolog suggests installing ext-mongo (Allow sending log messages to a MongoDB server)
monolog/monolog suggests installing aws/aws-sdk-php (Allow sending log messages to AWS services like DynamoDB)
monolog/monolog suggests installing rollbar/rollbar (Allow sending log messages to Rollbar)
behat/mink suggests installing behat/mink-zombie-driver (fast and JS-enabled headless driver for any app (requires node.js))
guzzle/guzzle suggests installing guzzlehttp/guzzle (Guzzle 5 has moved to a new package name. The package you have installed, Guzzle 3, is deprecated.)
phpunit/php-code-coverage suggests installing ext-xdebug (>=2.0.5)
phpunit/phpunit suggests installing phpunit/php-invoker (~1.1)
codeception/codeception suggests installing codeception/phpbuiltinserver (Extension to start and stop PHP built-in web server for your tests)
有些主题似乎无害，但有一些似乎很重要：
symfony/templating
symfony/security
和其他几个人
这些必不可少？如果是这样，它们不应该在composer.json文件中吗？