[utils] Numpy documentation webpage has moved

Fixes #74
4 jobs for numpy-1.18 in 3 minutes and 1 second (queued for 5 seconds)
Status Job ID Name Coverage
  Build
passed #191914
docker
build_linux_36

00:02:56

73.0%
passed #191915
docker
build_linux_37

00:02:56

73.0%
passed #191912
macosx
build_macosx_36

00:02:58

74.0%
passed #191913
macosx
build_macosx_37

00:02:48

74.0%