add contribution from @jharley to the README
add contribution from @jharley to the README

Sauraus/chef-percona,jharley/chef-percona,phlipper/chef-percona,notion/chef-percona,Sauraus/chef-percona,phlipper/chef-percona,twistle/chef-percona,mevansam/chef-cookbook-percona,jharley/chef-percona,bitpusher-real/chef-percona,archsaber/chef-percona,notion/chef-percona,twistle/chef-percona,engineyard-cookbooks/percona,archsaber/chef-percona,bitpusher-real/chef-percona