Update _version.py

Update README.md

Merge pull request danilop#75 from ewah/master

reset message w/ path

Fix to unlink directories without an object on S3.

Move/rename dirs now works recoursively to keep the cache updated.

S3 Requester Pays fix.

Multipart upload fix.

S3 writeback upload.

S3 writeback fix.

Get key cache optimization.