More rigorous tests
More rigorous tests

* ensuring inclusing of RGB extremes (0.0 -> 1.0) in the sample image
* LCH -> HUSL tests are run in a chained fashion. So the husl.py values are calculated separately (i.e. RGB -> LCH -> HSL) instead of relying on the husl-numpy library's LCH calculations. This reveals which part of the chain is failing, should there be a bug.

TadLeonard/husl-numpy,TadLeonard/husl-numpy,TadLeonard/husl-numpy