title: Execute native js promise in series
body: <p>I have to call a promise for some async task for each item in an array but I would like to execute these serially.</p>
  
  <p>Promise.all is useful only to have a new promise that merges a list of promise but it does not invoke them in a sequence.</p>
  
  <p>How can I achieve this using standard promise api without third-party libraries like Q, bluebird.... </p>