code: function adds(result, callback) {
                  let fns = policies.map(PolicyArn=> {
                    return function maybeAdd(callback) {
                      iam.attachRolePolicy({
                        RoleName,
                        PolicyArn
                      }, callback)
                    }
                  })
                  series(fns, callback)
                }
docs: attaches policies from role.json