Stop pinning to specific patch versions
Stop pinning to specific patch versions

This package should not require specific patch versions. Rather, it
should express the broadest range of possible versions that it supports.

In the current `setup.py`, we are very particular about which versions
must be used. Because of the specificity, installing `clrsvsim` makes
updating any other dependent libraries (e.g. `numpy`) quite difficult.

Modern dependency managers like `poetry` on `pipenv` will loudly
complain about dependency conflicts, making `clrsvism` a problematic
dependency.

Instead, we should just specify each of these as the *minimum* version
required. If there's some reason that the package does not support the
latest versions, then we can sort that out at a later time.

color/clrsvsim