defunkt/gist — pull request #137 by sdsykes (2013-04-27 13:00:21+00:00)
Title: Gist API now requires user-agent be set, and some versions of Net::HTTP don't

Creating gists will fail with 403 if the user-agent is not set, and versions of ruby such as 1.8.7 that comes with OSX have a version of Net::HTTP that doesn't set that header by default.