context managers

[jdamasco1]

To do for far future: use with...as... statements to help set up/teardown procedures for all instruments. Not doing so can possibly cause errors in trying to send commands or trying to connect.

Probably will need to look into __enter__ and __exit__ definitions for each class.

[jdamasco1]

This might be messy considering experiments can have multiple instruments....might have to do something like make a NEW class called experiment and allow it to take instruments that will automatically open/close when the experiment is opened or closed.