Changing working and workspace directory management

Created by: msanchezmartinez

This small PR should solve issue #7 (closed). It changes how the working directory is managed and is no longer assumed to be within the VLM repository. Furthermore, it adds the name of the script to the workspace folder so that results are not overwritten if there are two scripts in the same folder.

So, if folder aircraft has two scripts aircraft1.py and aircraft2.py, the code will create a workspace/aircraft_aircraft1 folder when running the first case and workspace/aircraft_aircraft2 when running the second. Both these folders will be within the current working directory.