title: The Angular CLI currently requires npm version 6
body: <p>I am using angular ng new command to create a application.</p>
  <p>ng new angular-hello-world.</p>
  <p>got below error.
  npm version 7.5.1 detected.
  The Angular CLI currently requires npm version 6.</p>
  <p>Please install a compatible version to proceed (<code>npm install --global npm@6</code>).</p>
  <p>any idea what it is ?  why need to install npm@6</p>