Bug fix for https://github.com/Ayrx/pyDropSecure/issues/1
Bug fix for https://github.com/Ayrx/pyDropSecure/issues/1

An MD5 checksum is used to detect modifications to a file. I have
converted self.local_files from a list to a {file:checksum} dict
in order to support this. In the case of directories, checksum
is None.

Ayrx/pyDropSecure