add example file for using IAM credentials
add example file for using IAM credentials

msonnabaum/chef-provisioning-aws,dawudrahmanaqovia/chef-provisioning-aws,brumschlag/chef-provisioning-aws,dcallao/chef-provisioning-aws,redterror/chef-provisioning-aws,Mindera/chef-provisioning-aws,avleen/chef-provisioning-aws,nitheeshp/chef-provisioning-aws,bbbco/chef-provisioning-aws,Jimflip/chef-provisioning-aws,mikenairn/chef-provisioning-aws,getaroom/chef-provisioning-aws,Fodoj/chef-provisioning-aws,chef/chef-provisioning-aws,ii/chef-provisioning-aws,RyanJarv/chef-provisioning-aws,chef/chef-provisioning-aws,dblessing/chef-provisioning-aws,miguelcnf/chef-provisioning-aws,tarak/chef-provisioning-aws