Remove instruction section on Debian keyring - script not available, also not...

Remove instruction section on Debian keyring - script not available, also not needed for a running a testing instance.

Signed-off-by: Mattia Rizzolo <mattia@debian.org>

README.md

@@ -70,13 +70,7 @@ Acquire some JSON data (ask Enrico at the moment) and import it:
 
     dc-tool --post --baseurl=http://localhost:8000 --source sourcename --auth-token sourcetoken datafile.json
 
-Sync Debian keyrings into data/keyrings/ :
-
-    ./synckeyrings.sh
-
-    eatmydata ./manage.py maintcarnivore
-
-Alternatively, to quickly generate some test data, run the following command:
+As a test, to quickly generate some test data, run the following command:
 
 ```bash
 eatmydata ./manage.py generate_test_data