Add logging of account allocation to accounts provider
Add logging of account allocation to accounts provider

This commit adds a log message to the locking accounts cred provider
to indicate when it has allocated a set of credentials successfully
from the accounts file. Right now when reading the tempest log file
during a run when using an accounts file there is no way to tell which
accounts where returned by the cred provider. This adds a info log msg
similar to what we log in isolated creds when it creates a new set of
creds. This should make it easier to trace through when credentials are
being allocated from the accounts file.

Change-Id: I82af7a3cba1e62cada94a9f4220666f1733e0575

Juniper/tempest,bigswitch/tempest,xbezdick/tempest,Juraci/tempest,NexusIS/tempest,afaheem88/tempest,roopali8/tempest,yamt/tempest,sebrandon1/tempest,openstack/tempest,cisco-openstack/tempest,xbezdick/tempest,openstack/tempest,tonyli71/tempest,manasi24/jiocloud-tempest-qatempest,tudorvio/tempest,neerja28/Tempest,nunogt/tempest,alinbalutoiu/tempest,neerja28/Tempest,Juniper/tempest,izadorozhna/tempest,jaspreetw/tempest,roopali8/tempest,vedujoshi/tempest,pandeyop/tempest,sebrandon1/tempest,LIS/lis-tempest,eggmaster/tempest,LIS/lis-tempest,pczerkas/tempest,hayderimran7/tempest,manasi24/tempest,jaspreetw/tempest,tonyli71/tempest,zsoltdudas/lis-tempest,JioCloud/tempest,flyingfish007/tempest,Tesora/tesora-tempest,varunarya10/tempest,bigswitch/tempest,danielmellado/tempest,masayukig/tempest,dkalashnik/tempest,cisco-openstack/tempest,flyingfish007/tempest,izadorozhna/tempest,dkalashnik/tempest,Tesora/tesora-tempest,NexusIS/tempest,danielmellado/tempest,varunarya10/tempest,hayderimran7/tempest,nunogt/tempest,manasi24/jiocloud-tempest-qatempest,vedujoshi/tempest,tudorvio/tempest,rakeshmi/tempest,pandeyop/tempest,masayukig/tempest,Juraci/tempest,akash1808/tempest,redhat-cip/tempest,redhat-cip/tempest,JioCloud/tempest,afaheem88/tempest,zsoltdudas/lis-tempest,yamt/tempest,pczerkas/tempest,manasi24/tempest,rakeshmi/tempest,alinbalutoiu/tempest,akash1808/tempest,eggmaster/tempest