[COOK-1087] Update the CONTRIBUTING file to fix a minor typo
[COOK-1087] Update the CONTRIBUTING file to fix a minor typo

dnsimple/chef-pdns,aetrion/pdns,sysbot/powerdns,aetrion/pdns,cookbooks/oc-pdns,dnsimple/chef-pdns,aetrion/pdns,sysbot/powerdns,cookbooks/hw-pdns