MDL-66979 behat: Warn about old behat.yml file location

admin/tool/behat/lang/en/tool_behat.php

@@ -46,6 +46,7 @@
 $string['theninfo'] = 'Then. Checkings to ensure the outcomes are the expected ones';
 $string['unknownexceptioninfo'] = 'There was a problem with Selenium or your browser. Please ensure you are using the latest version of Selenium. Error:';
 $string['viewsteps'] = 'Filter';
+$string['warndirrootconfigfound'] = 'A configuration file was found at {$a}. This file is not automatically updated and may become stale. We recommend removing this file.';
 $string['wheninfo'] = 'When. Action that provokes an event';
 $string['wrongbehatsetup'] = 'Something is wrong with the behat setup and so step definitions cannot be listed: <b>{$a->errormsg}</b><br/><br/>Please check:<ul>
 <li>$CFG->behat_dataroot, $CFG->behat_prefix and $CFG->behat_wwwroot are set in config.php with different values from $CFG->dataroot, $CFG->prefix and $CFG->wwwroot.</li>

lib/behat/classes/behat_command.php

@@ -179,7 +179,11 @@ public static function behat_setup_problem() {
         }
 
         // Behat test command.
-        list($output, $code) = self::run(' --help');
+        $dirrootconfigpath = $CFG->dirroot . DIRECTORY_SEPARATOR . 'behat.yml';
+        if (file_exists($dirrootconfigpath)) {
+            self::output_msg(get_string('warndirrootconfigfound', 'tool_behat', $dirrootconfigpath));
+        }
+        list($output, $code) = self::run(" --help");
 
         if ($code != 0) {