Feature/constraint analysis workshop updates

Disabling the gust and landing field length constraints caused the boundary vector to be empty, which resulted in errors. Fixed this issue

constraint_analysis/include/constraint_analysis/ca_functions.h

@@ -184,7 +184,10 @@ namespace Mattingly {
          */
         auto min_speed(double CL_max, double altitude, double Mach,  double weight_fraction) -> const double;
 
-        auto constraint_analysis::approach_speed(double V_app, double CL_max, double weight_fraction, double s_A, double C_D, double h_obs, double k_TD, double altitude) -> const double;
+        auto approach_speed(double V_app, double CL_max, double weight_fraction, double s_A, double C_D, double h_obs, double k_TD, double altitude) -> const double;
+
+        auto get_V_stall(double V_app, double k_TD, double CL_max, double CD, double h_obs, double s_A) -> const double;
+
     private:
 
         // Membervariables