Maybe replace dependency on codemod with another library?

[besfahbod]

pyanalyze/pyanalyze/node_visitor.py

Line 10 in b201328

import codemod

https://pypi.org/project/codemod/ hasn't been updated since 2017 and its cli doesn't even work under a PY3.6 environment anymore.

Maybe there's an alternative, up-to-date datatype we can use here, so we can retire the codemod package usage?

[JelleZijlstra]

We could perhaps also make the dependency optional; it's used only in rare cases.