Update oslo.utils minimal version

Commit Ib301466bb0a1996997c63599918fa96059a927bd added the usage
of oslo_utils md5 api which was added only in release 4.7.0.
Updating the requirements to accomodate this.
In addition, changing the requirements for other dependent libraries

Change-Id: Ia86208975cdc2e4261cb6cb20547d76ddb3ec571
1 file changed