offline signing issue

Im trying to sign transaction, but get this traceback

Traceback` (most recent call last):
  File "/usr/local/bin/piston", line 11, in <module>
    sys.exit(main())
  File "/usr/local/lib/python3.6/site-packages/pistoncli/__main__.py", line 1242, in main
    steem = Steem(**options)
  File "/usr/local/lib/python3.6/site-packages/piston/steem.py", line 133, in __init__
    self.rpc.register_apis(["account_by_key", "follow"])
AttributeError: 'NoneType' object has no attribute 'register_apis'

I get AttributeError: 'NoneType' object has no attribute 'register_apis' even if I am online. @xeroc

Updating steem seemed to solve the problem

pip3 install graphenelib --upgrade
pip3 install steem --upgrade

actually pip install steem installs a different library than piston.

@Netherdrake Oddly enough, graphenelib didn't update, but steem did, and immediately resolved the following error

AttributeError: 'NoneType' object has no attribute 'register_apis'

steem installs Piston fork, not Piston.