Adding missing test file for OSX

src/FiniteDifference/eq_unit_test.hpp

src/FiniteDifference/eq_unit_test_3d.hpp

src/PSE/Kernels_unit_tests.hpp

test/PSE_convergence_osx

...olver<double>_lid_driven_cavity_3d_p1_grid_0_test_osx.vtk

...olver<double>_lid_driven_cavity_3d_p2_grid_0_test_osx.vtk

...olver<double>_lid_driven_cavity_3d_p2_grid_1_test_osx.vtk

...olver<double>_lid_driven_cavity_3d_p3_grid_0_test_osx.vtk

...olver<double>_lid_driven_cavity_3d_p3_grid_1_test_osx.vtk

...olver<double>_lid_driven_cavity_3d_p3_grid_2_test_osx.vtk

...olver<double>_lid_driven_cavity_3d_p2_grid_0_test_osx.vtk

...olver<double>_lid_driven_cavity_3d_p2_grid_1_test_osx.vtk

...olver<double>_lid_driven_cavity_3d_p3_grid_0_test_osx.vtk

...olver<double>_lid_driven_cavity_3d_p3_grid_1_test_osx.vtk

...olver<double>_lid_driven_cavity_3d_p3_grid_2_test_osx.vtk

...k_solver<double>_lid_driven_cavity_p2_grid_0_test_osx.vtk

...k_solver<double>_lid_driven_cavity_p2_grid_1_test_osx.vtk

...k_solver<double>_lid_driven_cavity_p3_grid_0_test_osx.vtk

...k_solver<double>_lid_driven_cavity_p3_grid_1_test_osx.vtk

...k_solver<double>_lid_driven_cavity_p3_grid_2_test_osx.vtk