title: How to swipe down a UIViewController from another
body: <p>I don't know if the title is explicit so i'm going to explain it more here.
  I have at the moment an <strong><code>UIViewController</code></strong>, and a <strong><code>UIButton</code></strong> linked to a <strong><code>IBAction</code></strong> that fires another <code>UIViewController</code>. I would like to avoid this step of clicking by making the user swipe up, like dragging the other <code>UIViewController</code>. Everything i found was only <strong><code>UIGestureRecognizer</code></strong> but i can't find any controls or any tutorials to drag the <strong><code>UIViewController</code></strong>. 
  Basically, if i formulate this child-way, i would like to slide a <strong><code>UIViewcontroller</code></strong> from the bottom, with a one finger gesture, and that the <strong><code>UIViewController</code></strong> does follow my finger.
  Thanks for your help !</p>
  
  <p>EDIT : I don't use Storyboards, btw</p>