GetCommitRefs method added (#435)

* added commit missed functionality

* rename vars

* docs fix

* requested changes

* type mistype

commits.go

@@ -73,6 +73,7 @@ type ListCommitsOptions struct {
 	Until     *time.Time `url:"until,omitempty" json:"until,omitempty"`
 	Path      *string    `url:"path,omitempty" json:"path,omitempty"`
 	All       *bool      `url:"all,omitempty" json:"all,omitempty"`
+	WithStats *bool      `url:"with_stats,omitempty" json:"with_stats,omitempty"`
 }
 
 // ListCommits gets a list of repository commits in a project.
@@ -121,6 +122,49 @@ type CommitAction struct {
 	Encoding     string     `url:"encoding,omitempty" json:"encoding,omitempty"`
 }
 
+// CommitRef represents the reference of branches/tags in a commit.
+//
+// GitLab API docs:
+// https://docs.gitlab.com/ce/api/commits.html#get-references-a-commit-is-pushed-to
+type CommitRef struct {
+	Type string `json:"type"`
+	Name string `json:"name"`
+}
+
+// GetCommitRefsOptions represents the available GetCommitRefs() options.
+//
+// GitLab API docs:
+// https://docs.gitlab.com/ce/api/commits.html#get-references-a-commit-is-pushed-to
+type GetCommitRefsOptions struct {
+	ListOptions
+	Type *string `url:"type,omitempty" json:"type,omitempty"`
+}
+
+// GetCommitRefs gets all references (from branches or tags) a commit is pushed to
+//
+// GitLab API docs:
+// https://docs.gitlab.com/ce/api/commits.html#get-references-a-commit-is-pushed-to
+func (s *CommitsService) GetCommitRefs(pid interface{}, sha string, opt *GetCommitRefsOptions, options ...OptionFunc) ([]CommitRef, *Response, error) {
+	project, err := parseID(pid)
+	if err != nil {
+		return nil, nil, err
+	}
+	u := fmt.Sprintf("projects/%s/repository/commits/%s/refs", url.QueryEscape(project), sha)
+
+	req, err := s.client.NewRequest("GET", u, opt, options)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	var cs []CommitRef
+	resp, err := s.client.Do(req, &cs)
+	if err != nil {
+		return nil, resp, err
+	}
+
+	return cs, resp, err
+}
+
 // GetCommit gets a specific commit identified by the commit hash or name of a
 // branch or tag.
 //