Add additional checks for attributes
Add additional checks for attributes

Some decorators (like dtt) do have a func attribute
but no "attr" and "value" attribute defined.
This leads to errors during pep8 gate check (see [1]).

[1]: https://review.openstack.org/#/c/153234/4

Closes-Bug: #1431267
Change-Id: Id16bce40e30ecb6bc5bff9b55650acc538ece3a9

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