django "python manage.py validate" error : unknown command 'validate'
With this command:

pip install Django==1.8.2

the problem will be solved.
Django==1.9.2 does not support some commands.
With running this command:

python manage.py validate

I faced with this error:

Unknown command: 'validate'

What should I do now?
For more explanations:

Linux
Virtualenv
Python 3.4.3+
Django (1, 9, 2, 'final', 0)