Update scikit-image / Fiber Segmentation

[srivarra]

Scikit-image was pinned to v0.19.3 / v0.19.2 in #1060 because of a reimplementation of the frangi filter. This was over a year ago and causes the following issues:

• bounds the current versions of Python Ark can support
• bounds the current version of NumPy
• forces compilation of scikit image each time you create a new environment (several minutes each time)
• Doesn't allow us to use newer features in skimage if necessary later down the line.

We should find a way to get something comparable to this with the newer implementation.