keep all the .gitignore in one place

I always find it confusing when the list is spread over multiple files.

This reverts 063fc04a


that made all the content of /data/ not ignored.

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

.gitignore

@@ -6,3 +6,5 @@ nm2/local_settings.py
 *.gz
 /.coverage
 /htmlcov
+# there is a .keep file in there to keep /data/logs/ in the repository
+/data

data/logs/.gitignore

-/*.log*