Add Makefile entry that also gets rid of __pycache__

src/Makefile

@@ -1,2 +1,5 @@
 clean: 
-	rm *.o *.txt *.out *.exe
+	rm *.o *.txt *.out
+
+sclean:
+	sudo rm -rf *.o *.txt *.out __pycache__