Handled null repo, the case where a user deletes the repo referenced in the pull request.  Fixes #16.
Restore accidentally deleted test.
Merge pull request #17 from bac/issue-16

Handled null repo, the case where a user deletes the repo referenced in ...

...the pull request.  Fixes #16.
Fetch all pages of github comments

Comments on github issues, which covers pull requests, are paginated
in the github api. Update the comment fetching to get all pages by
navigating the link headers.
Merge pull request #18 from bz2/github_multiple_comment_pages

Fetch all pages of github comments

Comments on github issues, which covers pull requests, are paginated
in the github api. Update the comment fetching to get all pages by
navigating the link headers.
Fetch all pages of pull requests

Pull requests can be spread across multiple pages, so share the
link navigation code that was added for reading comments.
Merge pull request #19 from bz2/github_prs_multiple_pages

Fetch all pages of pull requests

Pull requests can be spread across multiple pages, so share the
link navigation code that was added for reading comments.

@binary132 discovered that his proposals were being ignored, the github api documentation doesn't state prs get paginated, but the same scheme is used as is for comments.