Make interactive_valve_test generic

[anushadatar]

Testing is a lot easier with the context of the python methods. Make the interactive valve test generic, probably like the serial test (this could just be "interactive test"). This will help make it easier to debug and make the tests more consistent as well.

Be sure to update the testing section of the software overview section of the wiki as part of this change.

[anushadatar]

Probably worth setting this up and testing it with using the bash script env variable method instead of cmd line args.