python 3 support

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Work plan

• add future imports: #1214
• set up CI to run against Python 3.6, block merge on regressions: #1234
• update dev docs: #1303
• fix one thing at a time (consider modernize):
  • cStringIO → io: #1272 let’s go with …
  • unlock test files: #1285
  • basestring -> six.string_types: #1286
  • mondo PR: #1376
• block merge on new test failures under Python 3: #1388
• fix remaining tests:
  • mu/lambda-related: #1400
  • one-offs: #1389
  • csv-related & remaining one-offs: #1396
• constrain runtime from local to lambda: #1546
• allow for changing runtimes: #1638
• allow for namespace packages in PythonPackageArchive: #1677
• port tools to start getting a feel for real use
  • index
  • logexporter
  • mailer: #1417
  • org
  • salactus
  • sentry: #1420
  • sphere11
  • sphinxext
  • traildb
• update docs w/ beta status for py36: #1519
• start running live
• fix bugs

[alfredgamulo]

Lambda now supports 3.6: https://aws.amazon.com/about-aws/whats-new/2017/04/aws-lambda-supports-python-3-6/

[skurfer]

I’ve tracked down the intermittent failure in test_cli.py @whit537. The Python 2 tests Pickle some data in ~/.cache/cloud-custodian.cache. When the tests run under Python 3, it loads that file and hits a UnicodeDecodeError.

There are options for pickle.load() that will fix this, but they’re only available under Python 3. I don’t think writing the file using Python 2 and reading it with Python 3 represents a real use-case that we need to worry about, so I’m not going to make any changes to the code, but maybe that cache should be wiped when tests are done.

As for the tools, I’ve only done light work on the mailer so I’m not too familiar, but if that’s what’s next, I’d be happy to start on them.