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

chef-cookbooks/webpi,kendrickm/webpi,lorieri/webpi,hh/webpi,jtimberman/webpi,cookbooks/oc-webpi,mcliment/webpi,daptiv/webpi,juliandunn/webpi,paulmooring/webpi,opscode-cookbooks/webpi,Youscribe/webpi-cookbook