Responsive container-fluid

Created by: fulldecent

FEATURE REQUEST: .container-*-fluid

DESCRIPTION: Switch to fluid layout for viewports larger than a certain size.

Use case: https://codepen.io/anon/pen/WXaoyo?editors=1100#0

Implementation for .container-xl-fluid:

@media (min-width: 1200px) {
  .container-xl-fluid {
    width: 100%;
    margin-right: auto;
    margin-left: auto;
    padding-right: 15px;
    padding-left: 15px;
    width: 100%;
    max-width: none;
  }
}