To get BlenderCAM to run, you need shapely and numpy. At least in macOS, blender comes with a bundled python version. The packages need to be installed in the bundled site_packages, but since the bundled python doesn't provide pip, you need to install it manually.
cd /Applications/Blender.app/Contents/Resources/2.78/python
wget https://bootstrap.pypa.io/get-pip.py
./bin/python3.5m ./get-pip.py --prefix /Applications/Blender.app/Contents/Resources/2.78/python
./bin/python3.5m bin/pip3 install shapely numpy