fix(test): Set max wrapper size to the largest breakpoint

$max-wrapper-width has to set on the largest breakpoint, otherwise it will never appear.

Instead of define the breakpoints by this...

```scss
$breakpoints: (
  'mobile-landscape' 480px,
  'smaller-tablet' 600px,
  'tablet' 768px,
  'tablet-landscape' $max-wrapper-width,
  'desktop' 1200px
);
```

...it has to be like this:

```scss
$breakpoints: (
  'mobile-landscape' 480px,
  'smaller-tablet' 600px,
  'tablet' 768px,
  'tablet-landscape' 920px,
  'desktop' $max-wrapper-width
);
```