Simplify OS cache mecahism
Simplify OS cache mecahism

Specinfra v2 handle one host per one process.
So need not to handle OS cache by host.

chorrell/specinfra,lurdan/specinfra,pfaffle/specinfra,RoboticCheese/specinfra,glenux/contrib-specinfra,stoned/specinfra,seroron/specinfra,minimum2scp/specinfra,sean-horn/specinfra,verisign/specinfra,ihassin/specinfra,hfm/specinfra,aibou/specinfra,k0kubun/specinfra,winebarrel/specinfra,edolnx/specinfra,skamithi/specinfra,chinthakagodawita/specinfra,electrical/specinfra,mactkg/specinfra,hideyuki/specinfra,bodgit/specinfra,uroesch/specinfra,chef-partners/specinfra-cisco,miketheman/specinfra,nurse/specinfra,sorah/specinfra,r7kamura/specinfra,mizzy/specinfra,thenexus6/specinfra,gh2k/specinfra,tacahilo/specinfra,elibus/specinfra,stefanhorning/specinfra,optimizely/specinfra,higanworks/specinfra,sergueik/specinfra,serverspec/specinfra