Use the issue's Session object on issue.milestone
Use the issue's Session object on issue.milestone

Without passing in "self" to the Milestone for the issue.milestone
attribute, we were getting a completely brand-new GitHubSession. This
meant that we were failing to use Betamax which caused our tests to be
unreliable and to bypass Betamax while running the test-suite.

sigmavirus24/github3.py