Minor fix - what pip-packages are required for Python scripts

AlexeyAB

2018-05-06 c9b8bdee1886df5f83973d91c3597c28f99a9e0c

 src/network.c

@@ -767,6 +767,11 @@
      free_layer(net.layers[i]);
   }
   free(net.layers);

   free(net.scales);
   free(net.steps);
   free(net.seen);

#ifdef GPU
   if (gpu_index >= 0) cuda_free(net.workspace);
   else free(net.workspace);