NumPy 1.19.3 release

1. 583901a convert shebang from python to python3 (#15687) by Changqing Li · 6 years ago
2. 958a6b5 DOC,MAINT: Build release notes during CircleCI step by Sebastian Berg · 6 years ago
3. bfe255f BUILD: move all test dependencies to ./test_requirements.txt by mattip · 6 years ago
4. 01cd5c9 TST, DOC: Upload devdocs and neps after circleci build (#10702) by Stefan van der Walt · 7 years ago
5. 37878bf TST: appveyor: Enable OpenBLAS via MinGW Gfortran by xoviat · 8 years ago