安装laravel的疑问
此前安装laravel的时候并未注意安装后的提示信息，只注意安装成功与否，今天在创建项目的时候发现多了很多不一样的信息，具体如下，记录一下，后面得到答案之后再做补充。
symfony/var-dumper suggests installing ext-intl (To show region name in time zone dump)
symfony/var-dumper suggests installing ext-symfony_debug ()
symfony/routing suggests installing doctrine/annotations (For using the annotation loader)
symfony/routing suggests installing symfony/config (For using the all-in-one router or any loader)
symfony/routing suggests installing symfony/dependency-injection (For loading routes from a service)
symfony/routing suggests installing symfony/expression-language (For using expression matching)
symfony/routing suggests installing symfony/yaml (For using the YAML loader)
paragonie/random_compat suggests installing ext-libsodium (Provides a modern crypto API that can be used to generate random bytes.)
symfony/event-dispatcher suggests installing symfony/dependency-injection ()
symfony/http-kernel suggests installing symfony/browser-kit ()
symfony/http-kernel suggests installing symfony/config ()
symfony/http-kernel suggests installing symfony/dependency-injection ()
symfony/console suggests installing symfony/lock ()
egulias/email-validator suggests installing ext-intl (PHP Internationalization Libraries are required to use the SpoofChecking validation)
ramsey/uuid suggests installing ircmaxell/random-lib (Provides RandomLib for use with the RandomLibAdapter)
ramsey/uuid suggests installing ext-libsodium (Provides the PECL libsodium extension for use with the SodiumRandomGenerator)
ramsey/uuid suggests installing ext-uuid (Provides the PECL UUID extension for use with the PeclUuidTimeGenerator and PeclUuidRandomGenerator)
ramsey/uuid suggests installing moontoast/math (Provides support for converting UUID to 128-bit integer (in string form).)
ramsey/uuid suggests installing ramsey/uuid-doctrine (Allows the use of Ramsey\Uuid\Uuid as Doctrine field type.)
ramsey/uuid suggests installing ramsey/uuid-console (A console application for generating UUIDs with ramsey/uuid)
symfony/translation suggests installing symfony/config ()
symfony/translation suggests installing symfony/yaml ()
monolog/monolog suggests installing aws/aws-sdk-php (Allow sending log messages to AWS services like DynamoDB)
monolog/monolog suggests installing doctrine/couchdb (Allow sending log messages to a CouchDB server)
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 graylog2/gelf-php (Allow sending log messages to a GrayLog2 server)
monolog/monolog suggests installing mongodb/mongodb (Allow sending log messages to a MongoDB server via PHP Driver)
monolog/monolog suggests installing php-amqplib/php-amqplib (Allow sending log messages to an AMQP server using php-amqplib)
monolog/monolog suggests installing php-console/php-console (Allow sending log messages to Google Chrome)
monolog/monolog suggests installing rollbar/rollbar (Allow sending log messages to Rollbar)
monolog/monolog suggests installing ruflin/elastica (Allow sending log messages to an Elastic Search server)
monolog/monolog suggests installing sentry/sentry (Allow sending log messages to a Sentry server)
league/flysystem suggests installing league/flysystem-aws-s3-v2 (Allows you to use S3 storage with AWS SDK v2)
league/flysystem suggests installing league/flysystem-aws-s3-v3 (Allows you to use S3 storage with AWS SDK v3)
league/flysystem suggests installing league/flysystem-azure (Allows you to use Windows Azure Blob storage)
league/flysystem suggests installing league/flysystem-cached-adapter (Flysystem adapter decorator for metadata caching)
league/flysystem suggests installing league/flysystem-eventable-filesystem (Allows you to use EventableFilesystem)
league/flysystem suggests installing league/flysystem-rackspace (Allows you to use Rackspace Cloud Files)
league/flysystem suggests installing league/flysystem-sftp (Allows you to use SFTP server storage via phpseclib)
league/flysystem suggests installing league/flysystem-webdav (Allows you to use WebDAV storage)
league/flysystem suggests installing league/flysystem-ziparchive (Allows you to use ZipArchive adapter)
league/flysystem suggests installing spatie/flysystem-dropbox (Allows you to use Dropbox storage)
league/flysystem suggests installing srmklive/flysystem-dropbox-v2 (Allows you to use Dropbox storage for PHP 5 applications)
laravel/framework suggests installing aws/aws-sdk-php (Required to use the SQS queue driver and SES mail driver (~3.0).)
laravel/framework suggests installing doctrine/dbal (Required to rename columns and drop SQLite columns (~2.5).)
laravel/framework suggests installing ext-pcntl (Required to use all features of the queue worker.)
laravel/framework suggests installing ext-posix (Required to use all features of the queue worker.)
laravel/framework suggests installing guzzlehttp/guzzle (Required to use the Mailgun and Mandrill mail drivers and the ping methods on schedules (~6.0).)
laravel/framework suggests installing league/flysystem-aws-s3-v3 (Required to use the Flysystem S3 driver (~1.0).)
laravel/framework suggests installing league/flysystem-cached-adapter (Required to use Flysystem caching (~1.0).)
laravel/framework suggests installing league/flysystem-rackspace (Required to use the Flysystem Rackspace driver (~1.0).)
laravel/framework suggests installing nexmo/client (Required to use the Nexmo transport (~1.0).)
laravel/framework suggests installing pda/pheanstalk (Required to use the beanstalk queue driver (~3.0).)
laravel/framework suggests installing predis/predis (Required to use the redis cache and queue drivers (~1.0).)
laravel/framework suggests installing pusher/pusher-php-server (Required to use the Pusher broadcast driver (~3.0).)
laravel/framework suggests installing symfony/dom-crawler (Required to use most of the crawler integration testing tools (~3.3).)
laravel/framework suggests installing symfony/psr-http-message-bridge (Required to psr7 bridging features (~1.0).)
psy/psysh suggests installing ext-pcntl (Enabling the PCNTL extension makes PsySH a lot happier :))
psy/psysh suggests installing ext-posix (If you have PCNTL, you'll want the POSIX extension as well.)
psy/psysh suggests installing ext-pdo-sqlite (The doc command requires SQLite to work.)
psy/psysh suggests installing hoa/console (A pure PHP readline implementation. You'll want this if your PHP install doesn't already support readline or libedit.)
filp/whoops suggests installing whoops/soap (Formats errors as SOAP responses)
sebastian/global-state suggests installing ext-uopz (*)
phpunit/phpunit-mock-objects suggests installing ext-soap (*)
phpunit/php-code-coverage suggests installing ext-xdebug (^2.5.5)
phpunit/phpunit suggests installing phpunit/php-invoker (^1.1)
phpunit/phpunit suggests installing ext-xdebug (*)这些全是laravel 5.5推荐的一些安装包或者php拓展，根据自己的需要进行安装。