Speedup testing added to test folder

diagramms/.$Evolution_01.drawio.bkp

src/testing/Epoch_Amdahls_speedup.pdf

src/testing/Epoch_Amdahls_speedup.png

src/testing/Epoch_Gustavsons_speedup.pdf

src/testing/Epoch_Gustavsons_speedup.png

src/testing/Epoch_runtime.pdf

src/testing/Epoch_runtime.png

src/testing/Epoch_runtime_inlet.pdf

src/testing/Epoch_runtime_inlet.png

src/testing/Speedup_figures.ipynb

src/testing/testing_notebook.ipynb