I think I might be doing something silly with my environment.
I'm trying to lint using tox in a dev container, but running tox ends with
this error:
```
(env) jtran@[Beam Build Env.]:~/beam {flatmapdefault} ]
$ tox
File "/usr/lib/python3/dist-packages/tox/reporter.py", line 32, in
__init__
self._reset(**kwargs)
File "/usr/lib/python3/dist-packages/tox/reporter.py", line 38, in _reset
self.tw = py.io.TerminalWriter()
AttributeError: module 'py' has no attribute 'io'
```
This is preventing me from linting (sorry to everyone on my PRs who keep
seeing linting errors...)
Any help here would be welcome. I've been struggling generally to get a
stable dev environment working.
Cheers,
Joey
