Replace setup.py with pyproject.toml

[aaraney]

Replace setup.py with pyproject.toml. This removed arbitrary code execution during packaging and specifies the required build tools needed for packaging.

Changes

• Package with pyproject.toml instead of setup.py
• Explicity set minimum python version to >=3.7. This was already implicit, see Hydrotools nwis-client requires python 3.7 #19 for details.

[robertbartel]

I have a couple of items to point out before final approval. I'm not certain either must be adjusted, but I'd like to sanity check them.

[robertbartel]

I suspect this needs to be adjusted, though I'm not exactly sure how. The LICENSE file doesn't exactly reference MIT.

[aaraney]

Great call, @robertbartel! I removed the license classifier.

[robertbartel]

I'm not super well versed with how this works, but I think setting dynamic = ["version"] will change the versioning scheme. That wasn't an explicitly mentioned change. Was this deliberate, or am I missing something about how this functions?

[aaraney]

@robertbartel, there is a little indirection going on that can be a little confusing. I had to double take the first time I saw this syntax. Here is the official documentation of the dynamic directive. In short, this tells the software that builds the package from the toml config file what portions of information are dynamically generated. In this case, we are getting the package version information from hypy._version.__version__. This is the same location we were previously getting version information from when we used setup.py. See:

[tool.setuptools.dynamic]
version = {attr = "hypy._version.__version__"}