Update description in graphite_storage provider specs.
Update description in graphite_storage provider specs.

tas50/graphite,mbabic/graphite,hw-cookbooks/graphite,diegobill/graphite,diegobill/graphite,bitmonk/chef-graphite,diegobill/graphite,bitmonk/chef-graphite,tas50/graphite,tas50/graphite,hw-cookbooks/graphite,hw-cookbooks/graphite,mbabic/graphite,mbabic/graphite,bitmonk/chef-graphite