他の人に Cloud9 環境への権限を与える方法のメモ。
ENV_ID=a46350721c354db29469c50050d95219 USER_ARN=arn:aws:sts::123456789012:assumed-role/Cloud9User/sotosugi-Isengard aws cloud9 create-environment-membership --environment-id ${ENV_ID} --user-arn ${USER_ARN} --permissions read-write