Adds the following optional parameters:
PULL_REQUEST_LABELS- A comma separated list of labels.PULL_REQUEST_ASSIGNEES- A comma separated list of assignees (GitHub usernames).PULL_REQUEST_REVIEWERS- A comma separated list of reviewers (GitHub usernames) to request a review from.PULL_REQUEST_TEAM_REVIEWERS- A comma separated list of GitHub teams to request a review from.PULL_REQUEST_MILESTONE- The number of the milestone to associate this pull request with.