Support ALICLOUD_SECURITY_TOKEN in environment variables

[Yong Zhang]

Hi, there

Thanks for sharing this project, this is great and very useful!

It would be nice to support ALICLOUD_SECURITY_TOKEN in environment variables, this will be used in aliyun terraform provider, thanks!!!

Ref:
https://registry.terraform.io/providers/aliyun/alicloud/latest/docs#security_token

[Huang Huang]

The latest version already supports it.