commandment 0.1 has requirement cryptography==2.1.4, but you'll have cryptography 2.2.2 which is incompatible.
pyopenssl 18.0.0 has requirement cryptography>=2.2.1, but you'll have cryptography 2.1.4 which is incompatible.
How to make it works? I mean how to install commandment?
ps: also doc says
"pip install -r ./requirements.txt"
but there is no such file.