added BC compatibility for disableRetryFailedStep

Author: DavertMik

lib/plugin/retryFailedStep.js

@@ -106,7 +106,9 @@ module.exports = config => {
   })
 
   event.dispatcher.on(event.test.before, test => {
-    if (test.opts.disableRetryFailedStep) {
+    // pass disableRetryFailedStep is a preferred way to disable retries
+    // test.disableRetryFailedStep is used for backward compatibility
+    if (test.opts.disableRetryFailedStep || test.disableRetryFailedStep) {
       store.autoRetries = false
       return // disable retry when a test is not active
     }