Skip incompatible test on OSX
Skip incompatible test on OSX

Can't seem to get the test:
cinder.tests.test_volume.VolumeTestCase.test_delete_no_dev_fails
to run right, tried macports and homebrew versions of fileutils
but still get makedir failures. Give up and just detect if OSX
and skip.

Change-Id: Ic2f7603cf2960e2fbaac9fce677461f60ded541d

Hybrid-Cloud/cinder,tlakshman26/cinder-bug-fix-volume-conversion-full,hguemar/cinder,openstack/cinder,leilihh/cinder,rakeshmi/cinder,bswartz/cinder,Paul-Ezell/cinder-1,winndows/cinder,Nexenta/cinder,saeki-masaki/cinder,nikesh-mahalka/cinder,manojhirway/ExistingImagesOnNFS,redhat-openstack/cinder,mahak/cinder,abusse/cinder,winndows/cinder,saeki-masaki/cinder,dims/cinder,JioCloud/cinder,apporc/cinder,sasukeh/cinder,Datera/cinder,CloudServer/cinder,ge0rgi/cinder,tlakshman26/cinder-bug-fix-volume-conversion-full,phenoxim/cinder,CloudServer/cinder,tlakshman26/cinder-new-branch,cloudbase/cinder,takeshineshiro/cinder,duhzecca/cinder,Nexenta/cinder,Akrog/cinder,eharney/cinder,takeshineshiro/cinder,potsmaster/cinder,NetApp/cinder,phenoxim/cinder,j-griffith/cinder,Akrog/cinder,dims/cinder,tlakshman26/cinder-new-branch,bswartz/cinder,duhzecca/cinder,scottdangelo/RemoveVolumeMangerLocks,openstack/cinder,potsmaster/cinder,blueboxgroup/cinder,petrutlucian94/cinder,scality/cinder,nexusriot/cinder,abusse/cinder,alex8866/cinder,github-borat/cinder,redhat-openstack/cinder,tlakshman26/cinder-https-changes,j-griffith/cinder,NetApp/cinder,julianwang/cinder,julianwang/cinder,mahak/cinder,JioCloud/cinder,petrutlucian94/cinder,Hybrid-Cloud/cinder,apporc/cinder,cloudbase/cinder,scality/cinder,leilihh/cinder,Accelerite/cinder,manojhirway/ExistingImagesOnNFS,blueboxgroup/cinder,scottdangelo/RemoveVolumeMangerLocks,tlakshman26/cinder-https-changes,sasukeh/cinder,Accelerite/cinder,nexusriot/cinder,Paul-Ezell/cinder-1,rakeshmi/cinder,github-borat/cinder,alex8866/cinder,Datera/cinder,nikesh-mahalka/cinder,hguemar/cinder,eharney/cinder