title: Make Bootstrap input group full width
body: <p>My problem is, that my <code>input-group</code>'s width is not 100%.</p>
  
  <p>This is how it looks at the moment: <a href="https://jsfiddle.net/6gmzz07b/" rel="noreferrer">https://jsfiddle.net/6gmzz07b/</a></p>
  
  <p>I just want, that the <code>input-group</code>'s width is 100%, so that it fills the container.</p>