Use os.urandom instead of OpenSSL.rand.bytes
Use os.urandom instead of OpenSSL.rand.bytes

Follows suggestion in pyOpenSSL changelog https://github.com/pyca/pyopenssl/blob/1eac0e8f9b3829c5401151fabb3f78453ad772a4/CHANGELOG.rst#backward-incompatible-changes-1
James1345/django-rest-knox,James1345/django-rest-knox