Fix time format used for cloud orchestration

The format used to represent time is slightly different than RFC
standard and the one present in golang time lib.
diff --git a/openstack/orchestration/v1/stackresources/results.go b/openstack/orchestration/v1/stackresources/results.go
index 69f21da..04a2334 100644
--- a/openstack/orchestration/v1/stackresources/results.go
+++ b/openstack/orchestration/v1/stackresources/results.go
@@ -48,7 +48,7 @@
 	for i, resourceRaw := range resources {
 		resource := resourceRaw.(map[string]interface{})
 		if date, ok := resource["updated_time"]; ok && date != nil {
-			t, err := time.Parse(time.RFC3339, date.(string))
+			t, err := time.Parse(gophercloud.STACK_TIME_FMT, date.(string))
 			if err != nil {
 				return nil, err
 			}
@@ -109,7 +109,7 @@
 	for i, resourceRaw := range resources {
 		resource := resourceRaw.(map[string]interface{})
 		if date, ok := resource["updated_time"]; ok && date != nil {
-			t, err := time.Parse(time.RFC3339, date.(string))
+			t, err := time.Parse(gophercloud.STACK_TIME_FMT, date.(string))
 			if err != nil {
 				return nil, err
 			}
@@ -143,7 +143,7 @@
 	resource := r.Body.(map[string]interface{})["resource"].(map[string]interface{})
 
 	if date, ok := resource["updated_time"]; ok && date != nil {
-		t, err := time.Parse(time.RFC3339, date.(string))
+		t, err := time.Parse(gophercloud.STACK_TIME_FMT, date.(string))
 		if err != nil {
 			return nil, err
 		}