使用terraform script去set up AWS

1. 准备好terraform script
2. Assume Role
3. terraform init
4. terraform plan --var-file env_vars/xxx.tfvars --out build.out
5. terraform apply "build.out"
6. set tf_log=trace
   set tf_log_path=./terraform.log (如果想加debug log的话就跑这两个命令)