python-3parclient.git install issues

[aix1]

[root@dlseelm-bb6006 pike]# pip install --upgrade python-3parclient
'Collecting python-3parclient
Using cached python-3parclient-4.2.5.tar.gz
Collecting paramiko (from python-3parclient)
Using cached paramiko-2.4.0-py2.py3-none-any.whl
Collecting eventlet (from python-3parclient)
Using cached eventlet-0.22.0-py2.py3-none-any.whl
Collecting requests (from python-3parclient)
Using cached requests-2.18.4-py2.py3-none-any.whl
Collecting cryptography>=1.5 (from paramiko->python-3parclient)
Using cached cryptography-2.1.4.tar.gz
Complete output from command python setup.py egg_info:
error in cryptography setup command: Invalid environment marker: python_version < '3'

----------------------------------------

Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-uPI1BK/cryptography/