New simulate method
This now keeps the Cantilever as a base class with relevant implementations and allows user to implement a parent that inherits this class.
Advantages:
- Makes the code for electricDrive its own file, same with MechanicalDrive
- Allows users to allow any arbitrary change (some exotic modification of the force) but keeps all the mild bookkeeping and large init file behind the scenes.
- MechanicalDrive is now edited to allow an arbitrary function passed as the excitation OR a voltage_array