Adding os-services in blockstorage api

Change-Id: I6ded5a930c4d43288053014cb77a946732f37f12
diff --git a/openstack/blockstorage/extensions/os-services/requests.go b/openstack/blockstorage/extensions/os-services/requests.go
new file mode 100644
index 0000000..487e679
--- /dev/null
+++ b/openstack/blockstorage/extensions/os-services/requests.go
@@ -0,0 +1,13 @@
+package os_services
+
+import (
+	gophercloud "gerrit.mcp.mirantis.net/debian/gophercloud.git"
+	"gerrit.mcp.mirantis.net/debian/gophercloud.git/pagination"
+)
+
+// List returns a Pager that allows you to iterate over a collection of Network.
+func List(client *gophercloud.ServiceClient) pagination.Pager {
+	return pagination.NewPager(client, listURL(client), func(r pagination.PageResult) pagination.Page {
+		return OsServicePage{pagination.SinglePageBase(r)}
+	})
+}