Fix typo in readme.markdown

Endore -> Endorse
Merge pull request #96 from ewanmellor/copy-from-copy-ref

Implement POST /<version>/fileops/copy using from_copy_ref.
Merge pull request #95 from ewanmellor/copy-ref

Implement GET /<version>/copy_ref/<root>/<path>.
Merge pull request #94 from DavidDeSloovere/master

Fixed typo
Merge remote-tracking branch 'dkarzon/master' into tipbit-master