Require Behat v3.15.0+ (#228)

Author: swissspidy

composer.json

@@ -10,7 +10,7 @@
     "type": "phpcodesniffer-standard",
     "require": {
         "php": ">=7.2.24",
-        "behat/behat": "^3.7",
+        "behat/behat": "^v3.15.0",
         "dealerdirect/phpcodesniffer-composer-installer": "^0.4.3 || ^0.5 || ^0.6.2 || ^0.7.1 || ^1.0.0",
         "php-parallel-lint/php-console-highlighter": "^1.0",
         "php-parallel-lint/php-parallel-lint": "^1.3.1",