NewCircleCiService creates a new CircleCi service.

NewCircleCiServiceWithGithubComments creates a new CircleCi service with an authenticated Github client.

branch that triggered the workflow.

diff against base branch if workflow triggered by PR.

optional user input variable if base branch is not master.

right side is reserved for additions and unchanged lines https://developer.github.com/v3/pulls/comments/#create-a-review-comment-for-a-pull-request.

Service contains the github client that makes Github api calls.