'Check Model2DKernel against Gaussian2Dkernel'

def test_model_2D_kernel(self):

    stddev = 5.0
    gauss = Gaussian2D((1.0 / ((2 * np.pi) * (stddev ** 2))), 0, 0, stddev, stddev)
    model_gauss_kernel = Model2DKernel(gauss, x_size=21)
    gauss_kernel = Gaussian2DKernel(stddev, x_size=21)
    assert_almost_equal(model_gauss_kernel.array, gauss_kernel.array, decimal=12)
