Updates method name in `#unshare_file` spec
Updates method name in `#unshare_file` spec

This will allow the doc tool to link the examples in the documentation.

Jesus/dropbox_api_v2,Jesus/dropbox_api,Jesus/dropbox_api,Jesus/dropbox_api_v2,Jesus/dropbox_api,Mavvie/dropbox_api,Mavvie/dropbox_api,Mavvie/dropbox_api