dependency updates

[smoench]

 - Updating nikic/php-parser (v4.1.1) to nikic/php-parser (v4.2.1)
  - Updating symfony/filesystem (v4.2.2) to symfony/filesystem (v4.2.3)
  - Updating symfony/config (v4.2.2) to symfony/config (v4.2.3)
  - Updating symfony/console (v4.2.2) to symfony/console (v4.2.3)
  - Updating symfony/dependency-injection (v4.2.2) to symfony/dependency-injection (v4.2.3)
  - Updating symfony/event-dispatcher (v4.2.2) to symfony/event-dispatcher (v4.2.3)
  - Updating symfony/finder (v4.2.2) to symfony/finder (v4.2.3)
  - Updating symfony/options-resolver (v4.2.2) to symfony/options-resolver (v4.2.3)
  - Updating symfony/yaml (v4.2.2) to symfony/yaml (v4.2.3)
  - Updating sebastian/environment (4.0.1) to sebastian/environment (4.1.0)
  - Updating sebastian/diff (3.0.1) to sebastian/diff (3.0.2)
  - Updating phpunit/php-timer (2.0.0) to phpunit/php-timer (2.1.1)
  - Updating phpunit/phpunit (7.5.1) to phpunit/phpunit (7.5.6)