Switch some oslo library jobs to voting

A few jobs in oslo.vmware, oslo.serialization, oslo.utils related to 
docs and requirements had trouble, we have fixed them and they are 
working well now. This review switches these handful of jobs to voting 
to ensure we don't break them again.

Change-Id: Icecf394dda84a57e88e2493d460a7009eb1d9497
Merge "Switch some oslo library jobs to voting"