Null checks are needed after all, there's no need to close WebDriver when the test hasn't created it

Author: mkrzyzanowski

bb-junit5/src/main/java/com/cognifide/qa/bb/junit5/selenium/WebdriverCloseExtension.java

@@ -51,7 +51,9 @@ public void beforeTestExecution(ExtensionContext context) {
    */
   @Override
   public void afterTestExecution(ExtensionContext context) {
-    webDriver.quit();
+    if (webDriver != null) {
+      webDriver.quit();
+    }
   }
 
   /**