Expand test range for FLiNaK unit test

    Thermophysical_Properties tp;

    ASSERT_TRUE(tp.initialize(&d));

    // Ensure that the composition set correctly

    ASSERT_TRUE(tp.setComposition({"LiF","NaF","KF"},{0.465,0.115,0.42}));

    EXPECT_NEAR(2.01770, tp.rho(900), 1e-5);

    // Test Density

    std::vector<double> tks           = {700.0, 750.0, 800.0, 850.0, 860.0, 1000.0};

    // Expected calculated values (note these have been rounded)

    std::vector<double> rho_calc_ref  = {2.1425,2.1113,2.0801,2.04890,2.04266,1.9553};

    for( size_t i = 0; i < tks.size(); ++i)

    {

        double t_k = tks[i];

        EXPECT_NEAR(rho_calc_ref[i], tp.rho(t_k), 5e-4);

    }

    EXPECT_NEAR(tp.rho_h(tp.h_t(900)), tp.rho(900), 1e-4);

    tks.clear();

    // Test Heat Capacity

    // Using values from reference https://doi.org/10.1021/je00029a041

    std::vector<double> tks           = {750, 800, 850, 860};

    // Experimental values

    // NOTE reference values are {17.50, 18.03, 18.55, 18.60} cal mol^-1 K^-1, but we use J mol^-1 K^-1

    std::vector<double> cp_exp       = {73.22, 75.43752, 75.43752, 77.8224};

    tks           = {700.0, 750.0, 800.0, 850.0, 860.0, 1000.0};

    // Expected calculated values (note these have been rounded)

    std::vector<double> cp_calc_ref  = {73.2255, 75.4194, 77.6133, 78.0521};

    std::vector<double> cp_calc_ref  = {71.0316, 73.2255, 75.4194, 77.6133, 78.0521, 84.195};

    std::cout << "Heat Capacity:" << std::endl

              << " T(K) experimental calc_ref calced" << std::endl;

    for( size_t i = 0; i < tks.size(); ++i)

    {

        double t_k = tks[i];

        EXPECT_NEAR(cp_calc_ref[i], tp.cp(t_k), 5e-4);

        // print data

        std::cout << t_k << " " << cp_exp[i]

                         << " " << cp_calc_ref[i]

                         << " " << tp.cp(t_k)

                         << " " << cp_calc_ref[i] - tp.mu(t_k) << std::endl;

    }

    EXPECT_NEAR(tp.cp_h(tp.h_t(1200)), tp.cp(1200), 4e-2);

    tks.clear();

    // Test Viscosity

    // Using values from reference https://doi.org/10.1021/je60084a007

    tks                              = {822.45, 872.65, 973.45, 922.95, 770.15};

    // Experimental values

    std::vector<double> mu_exp       =  {5.615,  4.097,  2.535,  3.156,  8.551};

    tks                              = {700.0, 822.45, 872.65, 973.45, 922.95, 770.15, 1000.0};

    // Expected calculated value

    std::vector<double> mu_calc_ref  = {5.6296, 4.0862, 2.5436, 3.1494, 8.5459};

    std::vector<double> mu_calc_ref  = {17.9814 , 5.6296, 4.0862, 2.5436, 3.1494, 8.5459, 2.3095};

    std::cout << "Viscosity :" << std::endl

              << " T(K) experimental calc_ref calced" << std::endl;

    for( size_t i = 0; i < tks.size(); ++i)

    {

        double t_k = tks[i];

        EXPECT_NEAR(mu_calc_ref[i], tp.mu(t_k), 5e-4);

        // print data

        std::cout << t_k << " " << mu_exp[i]

                         << " " << mu_calc_ref[i]

                         << " " << tp.mu(t_k)

                         << " " << mu_calc_ref[i] - tp.mu(t_k) << std::endl;

    }

    tks.clear();

    EXPECT_NEAR(tp.mu_h(tp.h_t(900)), tp.mu(900), 6e-4);

    // Test Thermal Conductivity

    // Using values from reference https://doi.org/10.1016/j.ijheatmasstransfer.2015.07.042

    tks                              = {773.0,  823.0,  873.0,  923.0,  973.0};

    // Experimental values

    std::vector<double> k_exp       = {0.6520, 0.7730, 0.7720, 0.8320, 0.9270};

    tks                              = {700.0, 773.0,  823.0,  873.0,  923.0,  973.0, 1000.0};

    // Expected calculated value

    std::vector<double> k_calc_ref  = {0.6549, 0.7199, 0.7849, 0.8499, 0.9149};

    std::vector<double> k_calc_ref  = {0.56, 0.6549, 0.7199, 0.7849, 0.8499, 0.9149, 0.95};

    std::cout << "Thermal Conductivity :" << std::endl

              << " T(K) experimental calc_ref calced" << std::endl;

    for( size_t i = 0; i < tks.size(); ++i)

    {

        double t_k = tks[i];

        EXPECT_NEAR(k_calc_ref[i], tp.k(t_k), 5e-4);

        // print data

        std::cout << t_k << " " << k_exp[i]

                         << " " << k_calc_ref[i]

                         << " " << tp.k(t_k)

                         << " " << k_calc_ref[i] - tp.mu(t_k) << std::endl;

    }

    EXPECT_NEAR(tp.k_h(tp.h_t(970)), tp.k(970), 1e-4);

    // Test temperature to enthalpy conversion

    EXPECT_NEAR(748.77235618, tp.t_h(1000), 1e-6);

    EXPECT_NEAR(tp.t_h(tp.h_t(970)),970,5e-2);

}