Update timeutils.py from oslo

This fix is related to oslo-incubator commits:
3bc6f79d794aee9d51abc0be10e846b971fae847
af76064855c5bb888e1a0d2800d1f49470e19091
df3f2bafbe76d78d017d40e7dc08909fee7dbe34

Change-Id: I1194df94d85d3dde29e81003c0c3db735c66b35f
Adding Read-Only volume attaching support to Nova

Supporting attach a volume with Read-Only mode in libvirt driver.

Implements bp: read-only-volumes

Related-Id: I4c84614d6541d5f7c358abadb957da7b8c3d9c48
Change-Id: Id5ef7b25350cb1bde9d30fbfa98fb7a80081827f
Signed-off-by: Zhi Yan Liu <lzy.dev@gmail.com>
Merge "Adding Read-Only volume attaching support to Nova"
Merge "Update timeutils.py from oslo"