title: migrate command not found error even if migrate is installed
body: <p>I have executed command - 
  <code>npm install migrate</code> 
  and it has executed successfully. But when I try to execute the command <code>migrate</code> in terminal it gives me error as <code>migrate command not found</code>
  <a href="http://i.stack.imgur.com/pUlS6.png" rel="noreferrer">Please find image here.</a></p>
  
  <p>Has anyone got the same error?</p>