add AdminListOrgs to list all orgs (#174)

Author: ngourdon

gitea/admin_org.go

@@ -1,4 +1,5 @@
 // Copyright 2015 The Gogs Authors. All rights reserved.
+// Copyright 2019 The Gitea Authors. All rights reserved.
 // Use of this source code is governed by a MIT-style
 // license that can be found in the LICENSE file.
 
@@ -12,6 +13,12 @@ import (
 	"code.gitea.io/gitea/modules/structs"
 )
 
+// AdminListOrgs lists all orgs
+func (c *Client) AdminListOrgs() ([]*Organization, error) {
+	orgs := make([]*Organization, 0, 10)
+	return orgs, c.getParsedResponse("GET", "/admin/orgs", nil, nil, &orgs)
+}
+
 // AdminCreateOrg create an organization
 func (c *Client) AdminCreateOrg(user string, opt structs.CreateOrgOption) (*Organization, error) {
 	body, err := json.Marshal(&opt)