Fixes to boto.s3.key stub (#2317)
Fixes to boto.s3.key stub (#2317)

* replace type comments in key.pyi

* reformat the file with black

* get_contents_as_string returns bytes unless an encoding is specified

http://boto.cloudhackers.com/en/latest/ref/s3.html#boto.s3.key.Key.get_contents_as_string

euresti/typeshed