listMilestones method
Lists all milestones for a repository.
API docs: https://developer.github.com/v3/issues/milestones/#list-milestones-for-a-repository
Implementation
Stream<Milestone> listMilestones(RepositorySlug slug) {
return PaginationHelper(github).objects(
'GET',
'/repos/${slug.fullName}/milestones',
(dynamic i) => Milestone.fromJson(i));
}