pyproject.toml and update mypy

pyproject.toml lets one specify the build requirements for the library.

Cython is required for cythonize.

Numpy and scipy are required for blas_ lapack pointers.

on my linux system typed-ast was having issues with the older version of
mypy (pyObject call issue).  0.9 worked with the current yapf version.

We may have to update the github workflow.  We will see...

Author: ncrubin

dev/conf/pip-list-dev-tools.txt

@@ -1,8 +1,8 @@
 # For testing and analyzing code.
-mypy~=0.701.0
+mypy~=0.910.0
 pylint~=2.4.0
 pytest-cov~=2.5.0
 yapf~=0.27.0
 
 # For notebook testing
-nbformat
+nbformat

pyproject.toml

@@ -0,0 +1,3 @@
+[build-system]
+requires = ["setuptools", "wheel", "Cython", "numpy", "scipy"]
+build-backend = "setuptools.build_meta"

requirements.txt

@@ -5,5 +5,4 @@ numpy>=1.14
 scipy
 pyasn1-modules==0.2.7
 Sphinx>=2.3.1
-typing
 Cython

setup.py

@@ -194,4 +194,5 @@ def main() -> None:
           cmdclass={'build_ext': CustomBuildOptions})
 
 
-main()
+if __name__ == "__main__":
+    main()