Updated a bunch of development dependencies, see details:

- Updating bitexpert/phpstan-magento dev-master (bddd248 => f7af124)
- Updating doctrine/instantiator (1.2.0 => 1.3.0)
- Updating friendsofphp/php-cs-fixer (v2.16.0 => v2.16.1)
- Updating myclabs/deep-copy (1.9.3 => 1.9.4)
- Updating phpcompatibility/php-compatibility (9.3.2 => 9.3.4)
- Updating phpdocumentor/reflection-docblock (4.3.2 => 4.3.3)
- Updating phpspec/prophecy (1.9.0 => 1.10.0)
- Updating phpunit/phpunit (7.5.17 => 7.5.18)
- Updating sebastian/environment (4.2.2 => 4.2.3)
- Updating squizlabs/php_codesniffer (3.5.2 => 3.5.3)
- Updating symfony/event-dispatcher (v4.3.6 => v4.4.2)
- Updating symfony/filesystem (v4.3.6 => v4.4.2)
- Updating symfony/finder (v4.3.6 => v4.4.2)
- Updating symfony/options-resolver (v4.3.6 => v4.4.2)
- Updating symfony/polyfill-ctype (v1.12.0 => v1.13.1)
- Updating symfony/polyfill-php70 (v1.12.0 => v1.13.1)
- Updating symfony/polyfill-php72 (v1.12.0 => v1.13.1)
- Updating symfony/service-contracts (v1.1.7 => v1.1.8)
- Updating symfony/stopwatch (v4.3.6 => v4.4.2)
- Updating webmozart/assert (1.5.0 => 1.6.0)

Author: hostep