FreeCodeCamp

Properly detect hex color codes in test.

Origenally you could pass all tests without ever placing the
hex code in the correct place, als abbreviates didn't work either
for background and hex code

- Can use the shortcode to pass the test now.
- Atleasts needs a body present with curly brackets
- Needs a background property being present in the body element
- The background property must be followed by a the proper hex color