[Bug] Obtain inconsistent STS tokens

[yesgibbs]

https://github.com/aliyun/credentials-python/blob/master/alibabacloud_credentials/credentials.py

The code here has correctness issues when the token cache is about to expire. The access_key, secret_key, and security_token form a triplet that must be used together. Currently, refreshing the token logic independently for each value retrieval could lead to inconsistencies in the upper layer obtaining mismatched AK/SK/token combinations during expiration boundaries. Instead of returning individual elements of the triplet separately, they should be enforced to be returned as a whole. This has essentially dug a pit for the calling code to fall into.

[yndu13]

OK, we already support the new way to obtain credentials, please use version 1.0.0 and above.

see: https://github.com/aliyun/credentials-python/blob/master/alibabacloud_credentials/provider/ecs_ram_role.py#L83