vhulk is ...buggy. Disabling it for now
- Added the cat_predictions.py that handles arbitrary number of input,
depending on the output that is there. All operations are done internally
with pandas. I replaces the hard coded bash scriplet that assumed all tools
had run

This reverts commit 0c51f51b.

The `directory` directive touches an empty file within the directory.
This causes WIsH to iterate over that file and messes its output. It
contains an empty string as contig and contains an empty phage entry
with a random taxonomy assignment. By making it a parameter for the
rules the dir only contains fasta files.