request to add single smu current sweep function

[soha-namnabat]

Hi,
I like the package and I need a function that does current sweep similar to voltage_sweep_single_smu. Would you be able to add this?

thanks
Soha

[samschott]

@soha-namnabat, since I am longer working in a lab these days, this package is very much in maintenance mode. However, I am happy to review pull requests.