Jacobian fix runtests.jl

Jacobian fix for tests.

Author: ParasPuneetSingh

lib/OptimizationODE/test/runtests.jl

@@ -233,7 +233,7 @@ end
             x = [1.0, 2.0]
             f(x) = [x[1]^2 + x[2], x[1] * x[2]]
 
-            J = OptimizationODE.finite_difference_jacobian(f, x)
+            J = ForwardDiff.jacobian(f, x)
 
             expected_J = [2.0 1.0; 2.0 1.0]
 
@@ -287,4 +287,4 @@ end
             @test isapprox(sol.u[1], p[1], atol=1e-1)
         end
     end
-end
+end