bst-artifact-receive does not require bubblewrap

I just tried installing BuildStream on the server which will be hosting my artefacts cache.

$ python3 setup.py install --user
Bubblewrap not found: BuildStream requires Bubblewrap (bwrap) for sandboxing the build environment. Install it using your package manager (usually bwrap or bubblewrap)

Having a way to install only bst-artifact-receive, or even a way to bypass the check for bubblewrap would be nice. 😃