minor #560 Recommend to use Symfony Flex for installation (dunglas)
minor #560 Recommend to use Symfony Flex for installation (dunglas)

This PR was merged into the 5.1.x-dev branch.

Discussion
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Recommend to use Symfony Flex for installation

Commits
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ddbe432 Recommend to use Symfony Flex for installation

sensiolabs/SensioFrameworkExtraBundle