------------------ - Fix refreshing of local credentials on failure, streamline logic
1.5.0
------------------ - Add support for ``aws_security_token``/``aws_ssion_token``/``expiration`` in configuration files - Add support for ``AWS_SECURITY_TOKEN``/``AWS_SESSION_TOKEN`` environment variable config
1.4.0
------------------ - Add support for credentials files when refreshing credentials
1.3.0
------------------ - Add support for Python 3.7 - Drop support for versions of tornado < 5.0
1.2.0
------------------ - Add ``force_instance`` option when creating the client to disable instance isolation (8) - Fix a bug where we assume amz-jz error responses will include a message
1.1.1
------------------ - Don't convert str to bytes in Python 2 when making headers