BibTasklets: new tasklet

* to harvest from EDP Sciences
  FTP server.

Signed-off-by: Georgios Papoutsakis <georgios.papoutsakis@cern.ch>
It feels a bit hackish to create directory and remove it after. Maybe more pythonic to do something like:

```
if not os.path.exists(directory):
    os.makedirs(directory)
```