Import webapp2 instead of google.appengine.ext.webapp

[puccia]

This choice is apparently more robust in situations / runtimes where the import mechanism in google/appengine/ext/webapp/__init__.py does not appear to do the right thing.

[googlebot]

Thanks for your pull request. It looks like this may be your first contribution to a Google open source project, in which case you'll need to sign a Contributor License Agreement (CLA).

📝 Please visit https://cla.developers.google.com/ to sign.

Once you've signed, please reply here (e.g. I signed it!) and we'll verify. Thanks.

---

• If you've already signed a CLA, it's possible we don't have your GitHub username or you're using a different email address. Check your existing CLA data and verify that your email is set on your git commits.
• If you signed the CLA as a corporation, please let us know the company's name.

[puccia]

Covered by Google's own corporate agreement.

[craigcitro]

yep, googlebot is confused because you're not (yet) in the google org. no worries there.

it looks like the docs build is failing; likely we just need to add webapp2 to the list of packages we install for the docs build? are you familiar enough with tox that you could give it a shot? (you can just run tox -e docs locally to try it out, once you pip install tox as needed).

[puccia]

Exactly what you wrote! Looks healthy now.