add Team.Privacy field

update CreateTeam and EditTeam to pass preview media type if
Team.Privacy is set.

Ref #187

github/orgs_teams.go

@@ -22,6 +22,13 @@ type Team struct {
 	// specifying a permission value when calling AddTeamRepo.
 	Permission *string `json:"permission,omitempty"`
 
+	// Privacy identifies the level of privacy this team should have.
+	// Possible values are:
+	//     secret - only visible to organization owners and members of this team
+	//     closed - visible to all members of this organization
+	// Default is "secret".
+	Privacy *string `json:"privacy,omitempty"`
+
 	MembersCount *int          `json:"members_count,omitempty"`
 	ReposCount   *int          `json:"repos_count,omitempty"`
 	Organization *Organization `json:"organization,omitempty"`
@@ -84,6 +91,10 @@ func (s *OrganizationsService) CreateTeam(org string, team *Team) (*Team, *Respo
 		return nil, nil, err
 	}
 
+	if team.Privacy != nil {
+		req.Header.Set("Accept", mediaTypeOrgPermissionPreview)
+	}
+
 	t := new(Team)
 	resp, err := s.client.Do(req, t)
 	if err != nil {
@@ -103,6 +114,10 @@ func (s *OrganizationsService) EditTeam(id int, team *Team) (*Team, *Response, e
 		return nil, nil, err
 	}
 
+	if team.Privacy != nil {
+		req.Header.Set("Accept", mediaTypeOrgPermissionPreview)
+	}
+
 	t := new(Team)
 	resp, err := s.client.Do(req, t)
 	if err != nil {

github/orgs_teams_test.go

@@ -64,13 +64,14 @@ func TestOrganizationsService_CreateTeam(t *testing.T) {
 	setup()
 	defer teardown()
 
-	input := &Team{Name: String("n")}
+	input := &Team{Name: String("n"), Privacy: String("closed")}
 
 	mux.HandleFunc("/orgs/o/teams", func(w http.ResponseWriter, r *http.Request) {
 		v := new(Team)
 		json.NewDecoder(r.Body).Decode(v)
 
 		testMethod(t, r, "POST")
+		testHeader(t, r, "Accept", mediaTypeOrgPermissionPreview)
 		if !reflect.DeepEqual(v, input) {
 			t.Errorf("Request body = %+v, want %+v", v, input)
 		}
@@ -98,13 +99,14 @@ func TestOrganizationsService_EditTeam(t *testing.T) {
 	setup()
 	defer teardown()
 
-	input := &Team{Name: String("n")}
+	input := &Team{Name: String("n"), Privacy: String("closed")}
 
 	mux.HandleFunc("/teams/1", func(w http.ResponseWriter, r *http.Request) {
 		v := new(Team)
 		json.NewDecoder(r.Body).Decode(v)
 
 		testMethod(t, r, "PATCH")
+		testHeader(t, r, "Accept", mediaTypeOrgPermissionPreview)
 		if !reflect.DeepEqual(v, input) {
 			t.Errorf("Request body = %+v, want %+v", v, input)
 		}