func (s *RepositoriesService) GetCombinedStatus(ctx context.Context, owner, repo, ref string, opt *ListOptions) (*CombinedStatus, *Response, error) {
	u := fmt.Sprintf("repos/%v/%v/commits/%v/status", owner, repo, ref)
	u, err := addOptions(u, opt)
	if err != nil {
		return nil, nil, err
	}
	req, err := s.client.NewRequest("GET", u, nil)
	if err != nil {
		return nil, nil, err
	}
	status := new(CombinedStatus)
	resp, err := s.client.Do(ctx, req, status)
	if err != nil {
		return nil, resp, err
	}
	return status, resp, nil
}
GetCombinedStatus returns the combined status of a repository at the specified
reference. ref can be a SHA, a branch name, or a tag name.

GitHub API docs: https://developer.github.com/v3/repos/statuses/#get-the-combined-status-for-a-specific-ref
package github
import (
	"context"
	"fmt"
	"time"
)
type RepoStatus struct {
	ID  *int64  `json:"id,omitempty"`
	URL *string `json:"url,omitempty"`
	State *string `json:"state,omitempty"`
	TargetURL *string `json:"target_url,omitempty"`
	Description *string `json:"description,omitempty"`
	Context *string `json:"context,omitempty"`
	Creator   *User      `json:"creator,omitempty"`
	CreatedAt *time.Time `json:"created_at,omitempty"`
	UpdatedAt *time.Time `json:"updated_at,omitempty"`
}
func (r RepoStatus) String() string {
	return Stringify(r)
}
func (s *RepositoriesService) ListStatuses(ctx context.Context, owner, repo, ref string, opt *ListOptions) ([]*RepoStatus, *Response, error) {
	u := fmt.Sprintf("repos/%v/%v/commits/%v/statuses", owner, repo, ref)
	u, err := addOptions(u, opt)
	if err != nil {
		return nil, nil, err
	}
	req, err := s.client.NewRequest("GET", u, nil)
	if err != nil {
		return nil, nil, err
	}
	var statuses []*RepoStatus
	resp, err := s.client.Do(ctx, req, &statuses)
	if err != nil {
		return nil, resp, err
	}
	return statuses, resp, nil
}
func (s *RepositoriesService) CreateStatus(ctx context.Context, owner, repo, ref string, status *RepoStatus) (*RepoStatus, *Response, error) {
	u := fmt.Sprintf("repos/%v/%v/statuses/%v", owner, repo, ref)
	req, err := s.client.NewRequest("POST", u, status)
	if err != nil {
		return nil, nil, err
	}
	repoStatus := new(RepoStatus)
	resp, err := s.client.Do(ctx, req, repoStatus)
	if err != nil {
		return nil, resp, err
	}
	return repoStatus, resp, nil
}
type CombinedStatus struct {
	State *string `json:"state,omitempty"`
	Name       *string      `json:"name,omitempty"`
	SHA        *string      `json:"sha,omitempty"`
	TotalCount *int         `json:"total_count,omitempty"`
	Statuses   []RepoStatus `json:"statuses,omitempty"`
	CommitURL     *string `json:"commit_url,omitempty"`
	RepositoryURL *string `json:"repository_url,omitempty"`
}
func (s CombinedStatus) String() string {
	return Stringify(s)
}