chroma.average Error with 'lrgb' mode #187

Hello,
This library is absolutely incredible! Thank you very much for your work on it.

I noticed a bug when averaging an array of colors with the mode set to 'lrgb.' It outputs the color black and throws this error:

"unknown format: 154.74602848969448,99.85600744182706,158.8000139938421,1.0000000000000002"

Here's a Codepen demonstrating the bug.

Thanks again!