ModuleNotFoundError: No module named 'skbuild'

This happens when I try to build the XBrain Docker image:
```
Best match: blosc 1.9.0
Processing blosc-1.9.0.tar.gz
Writing /tmp/easy_install-0ynohjo8/blosc-1.9.0/setup.cfg
Running blosc-1.9.0/setup.py -q bdist_egg --dist-dir /tmp/easy_install-0ynohjo8/blosc-1.9.0/egg-dist-tmp-y7gzbzg1
Traceback (most recent call last):
File "/opt/conda/lib/python3.6/site-packages/setuptools/sandbox.py", line 154, in save_modules
yield saved
File "/opt/conda/lib/python3.6/site-packages/setuptools/sandbox.py", line 195, in setup_context
yield
File "/opt/conda/lib/python3.6/site-packages/setuptools/sandbox.py", line 250, in run_setup
_execfile(setup_script, ns)
File "/opt/conda/lib/python3.6/site-packages/setuptools/sandbox.py", line 45, in _execfile
exec(code, globals, locals)
File "/tmp/easy_install-0ynohjo8/blosc-1.9.0/setup.py", line 18, in
# get the dependencies and installs
ModuleNotFoundError: No module named 'skbuild'
```

It happens while building in on a Mac as well as Ubuntu 18.