add script for simple random read generation
diff --git a/genomix/genomix-hadoop/src/test/python/convert_graphviz.py b/genomix/genomix-hadoop/src/test/python/convert_graphviz.py
index fe9b778..4130052 100755
--- a/genomix/genomix-hadoop/src/test/python/convert_graphviz.py
+++ b/genomix/genomix-hadoop/src/test/python/convert_graphviz.py
@@ -100,7 +100,7 @@
 
     parser.add_argument('txt_graphs', nargs='*')
     parser.add_argument('--directory', '-d', help='Recurse here and plot all '
-                        'graphs that are found.', nargs='+', default=[])
+                        'graphs that are found.', action='append', default=[])
     return parser