- s/aws_key/aws_access_key_id/
- s/aws_secret/aws_secret_access_key/
- s/aws_token/aws_session_token/
rename them to more popular names, these names are also used by
boto's API. this should improve the readability and consistency.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>