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

mattjalexander/openldap,john5223/openldap,niku/openldap,PaytmLabs/chef-openldap,HomesiteInsurance/openldap,skemper/openldap,tomduckering/openldap,dcallao/openldap,openitdotcom/chef-openldap,computerlyrik/openldap,tknetworks-cookbooks/openldap,opscode-cookbooks/openldap,StepInfo/openldap,cookbooks/oc-openldap,cpuguy83/openldap,blasdelf/openldap,chef-cookbooks/openldap,HomesiteInsurance/openldap,fatboy/openldap,epcim/openldap,John-Appleseed/openldap,pwillred/openldap,broadinstitute/openldap,apealive-cookbooks/openldap,temujin9/openldap,opscode-cookbooks/openldap,dcallao/openldap,chef-cookbooks/openldap,mattjalexander/openldap,PaytmLabs/chef-openldap,johnbellone/openldap,rackspace-cookbooks/openldap-deprecated,fatboy/openldap,skemper/openldap,glensc/chef-cookbook-openldap,kuleszaj/openldap,someara/openldap