Fixing test for GCC5

...lver<double>_lid_driven_cavity_3d_p1_grid_0_test_GCC5.vtk

...lver<double>_lid_driven_cavity_3d_p2_grid_0_test_GCC5.vtk

...lver<double>_lid_driven_cavity_3d_p2_grid_1_test_GCC5.vtk

...lver<double>_lid_driven_cavity_3d_p3_grid_0_test_GCC5.vtk

...lver<double>_lid_driven_cavity_3d_p3_grid_1_test_GCC5.vtk

..._solver<double>_lid_driven_cavity_p1_grid_0_test_GCC5.vtk

..._solver<double>_lid_driven_cavity_p2_grid_0_test_GCC5.vtk

..._solver<double>_lid_driven_cavity_p2_grid_1_test_GCC5.vtk

..._solver<double>_lid_driven_cavity_p3_grid_0_test_GCC5.vtk

..._solver<double>_lid_driven_cavity_p3_grid_1_test_GCC5.vtk