Version 0.0.2

New error class ContributionChecker::InvalidCommitUrlError to the rescue:

>> checker = ContributionChecker::Checker.new \
?>  :access_token => "<Your 40 char GitHub API token>",
?>  :commit_url   => "https://github.com/..."
>> checker.check
ContributionChecker::InvalidCommitUrlError: Invalid commit URL provided