Add num_instance_constraints to constraints and ensure that squeeze s…

…pecified values for the case of single unknown trajectories

opty/direct_collocation.py

@@ -745,6 +745,7 @@ def __init__(self, equations_of_motion, state_symbols,
                 self._generate_timeshift_constraints()
                 self._precalc_timshift_input_derivatives()
             self.num_instance_constraints = len(self.instance_constraints)
+            self.num_constraints += self.num_instance_constraints
             self._identify_functions_in_instance_constraints()
             self._find_closest_free_index()
             self.eval_instance_constraints = self._instance_constraints_func()
@@ -1957,6 +1958,9 @@ def constraints(free):
             eom_con_vals = func(free_states, all_specified, all_constants,
                                 time_interval)
 
+            if all_specified.shape[0] == 1:
+                all_specified.squeeze()
+
             if self.instance_constraints is not None:
                 if typ == 'con':
                     ins_con_vals = self.eval_instance_constraints(free)