Log Message:
py-colour: update to 0.1.4

0.1.4:
Fix
- ``rgb2hsl`` would produce invalid hsl triplet when red, blue, green
  component would be all very close to ``1.0``.

  Typically, saturation would shoot out of range 0.0..1.0. That could then
  lead to exceptions being casts afterwards when trying to reconvert this
  HSL triplet to RGB values.