Index the solution better in the test

Author: nathanaelbosch

test/ode_appxtrue_tests.jl

@@ -18,7 +18,7 @@ test_sol = TestSolution(sol2)
 errsol2 = appxtrue(sol4, test_sol)
 
 sol5 = solve(prob, Euler(); dt = 1 // 2^(4))
-test_sol = TestSolution(sol2.t, sol2[end])
+test_sol = TestSolution(sol2.t, sol2.u[end])
 errsol3 = appxtrue(sol5, test_sol)
 
 @test errsol1.errors[:L2] ≈ 0.018865798306718855