stub `rpm` command in `cluster_spec`
stub `rpm` command in `cluster_spec`

Sauraus/chef-percona,twistle/chef-percona,bitpusher-real/chef-percona,notion/chef-percona,twistle/chef-percona,bitpusher-real/chef-percona,jharley/chef-percona,phlipper/chef-percona,archsaber/chef-percona,jharley/chef-percona,phlipper/chef-percona,notion/chef-percona,Sauraus/chef-percona,archsaber/chef-percona