jupyter/nbviewer — pull request #386 by minrk (2014-12-21 00:59:34+00:00)
Title: fix a couple regressions in recent PRs

- str.encode('string_escape') doesn't exist in Python 3
- use app_log, not self.log in GitHubClient
- only warn about the absence of rate headers on successful requests (400 doesn't always include rate headers)

closes #385