Demo is broken

[Akababa]

Traceback (most recent call last):
  File "C:/Users/micha/dev/warpath-bot/adb_demo.py", line 4, in <module>
    from adb import sign_cryptography
ImportError: cannot import name 'sign_cryptography' from 'adb' (D:\ProgramData\Anaconda3\lib\site-packages\adb\__init__.py)

[ralexander-phi]

Check the old version of the README:

https://github.com/google/python-adb/blob/c610a56fb65c46b6438ac7d6a05faf07b44d5485/README.md#using-as-a-python-library

This was changed since version 1.3.0.