fix readme

README.md

@@ -54,18 +54,18 @@ Below is an example of 5 tasks with 2 steps to execute for each. Each step has a
   })
 
   runner
-    .on('error', (runner, key) => {
+    .on('error', (key, error) => {
       // one of tasks had an error on one of steps
       // key is key of task
     })
-    .on('task-done', (runner, key) => {
+    .on('task-done', (key) => {
       // one of tasks completed all steps with no error
 
       // log the task with results
       console.log(runner.tasks[key].serialize())
       // logs something like: { seconds: 0.3, success: true, step1: 'some result 1'}
     })
-    .on('complete', (runner) => {
+    .on('complete', () => {
       // all the tasks completed all steps
       // if any of them had errors
       // tryCounts are exhausted