title: Bootstrap 4: remove columns margin gutter
body: <p>I'm using Bootstrap 4 in an Angular project and i have noticed that the framework automatically put some left margin when using the <code>.col</code> class.
  The problem is that i can't remove that margin because even the inspector tell me that margin is <code>none</code>.</p>
  
  <p><a href="https://i.stack.imgur.com/vF8CD.png" rel="nofollow noreferrer">screen</a></p>
  
  <p>How do i do?</p>