fix for residue grid search

Author: skfegan

CodeEntropy/levels/search.py

@@ -236,5 +236,6 @@ def get_grid_neighbors(self, universe, mol_id, highest_level):
             # Make sure that the neighbors list does not include
             # residues from the central molecule
             neighbors = search - fragment.residues
+            neighbors = neighbors.atoms
 
         return neighbors.fragindices