Update surrogate code for new series return vals

Author: rsomers1998

causal_testing/surrogate/surrogate_search_algorithms.py

@@ -46,7 +46,7 @@ def fitness_function(ga, solution, idx): # pylint: disable=unused-argument
 
                 ate = surrogate.estimate_ate_calculated(adjustment_dict)
 
-                return contradiction_function(ate)
+                return contradiction_function(ate[0])
 
             gene_types, gene_space = self.create_gene_types(surrogate, specification)