Fixed request_id data type error under py3
Fixed request_id data type error under py3

In python3.4 request_id becomes a bytesarrary which is not JSON
serializable. This patch addes a conversion (safe_decode) wrapper.

Change-Id: Icf8dbf100ed2cb844e4922ea05e606588cb6e5e4

tengqm/senlin-container,Alzon/senlin,openstack/senlin,openstack/senlin,stackforge/senlin,Alzon/senlin,tengqm/senlin-container,openstack/senlin,stackforge/senlin