False positive with R503 inside with clause

[thehesiod]

• Date you used flake8-return: 8/16/2019
• flake8-return version used, if any: 1.1.0
• Python version, if any: 3.6.6
• Operating System: OSX

Description

With a function like the following:

async def function():
    async with thing as foo:
        return foo.bar

This is valid because there can be no other return than the one inside the with context. If enter/exit raise then nothing after it will run. The one way this is not true is if you capture the exeption with a try/except around the async with clause.

[afonasev]

I'll try to fix it soon, thx