remove test that uses non-public api

Author: SimonBlanke

tests/test_api/test_constr_opt.py

@@ -76,6 +76,7 @@ def constraint_1(para):
     assert np.all(x0_values > -5)
 
 
+"""
 def test_constr_opt_2():
     n_iter = 50
 
@@ -150,3 +151,4 @@ def constraint_2(para):
     assert n_best_positions <= n_new_positions
 
     assert n_new_positions == n_new_scores
+"""