fix: change path for building doc on circleci enh: removed useless WindowError and cythonize.dat in _build_utils init
Minor PEP8 fixes
pip installs would fail when compiling against ATLAS. This is due to a distutils-setuptools issue with monkeypatching that is triggered if Cython is imported. See https://github.com/numpy/numpy/issues/7235 for details.