Minor updates in require (#10)

Author: Nyholm

composer.json

@@ -15,7 +15,7 @@
         "symfony/runtime": "5.x-dev"
     },
     "require-dev": {
-        "symfony/phpunit-bridge": "5.x-dev"
+        "symfony/phpunit-bridge": "^5.2"
     },
     "autoload": {
         "psr-4": {