Syntax Error: ‘async’ is a reserved word in Python >= 3.7

[cclauss]

flake8 testing of https://github.com/google/active-qa on Python 3.7.0

$ flake8 . --count --select=E901,E999,F821,F822,F823 --show-source --statistics

./px/environments/docqa.py:72:20: E999 SyntaxError: invalid syntax
               async=0,
                   ^
1     E999 SyntaxError: invalid syntax

[j5b]

Thanks for reporting! We only ran this code with python2, so python3 may be broken. However, we're happy to accept fixes that enable python3 support.