title: when `npm login` with correct account and password , why still get 'Incorrect username or password'?
body: <p>I cannot use my pair of username and password to run <code>npm login</code> success in terminal, while </p>
  
  <p>I use a pair of account and password to login npmjs.com website. But when execute <code>npm login</code> in terminal, this error appeared:</p>
  
  <pre><code>npm WARN adduser Incorrect username or password
  npm WARN adduser You can reset your account by visiting:
  npm WARN adduser
  </code></pre>