Add support for Red Pitaya

[scasagrande]

The Red Pitaya is a neat little IO board with a bunch of open source components. It has a headless SCPI mode with a documented API, so I figured we might as well support it! If anything, maybe it'll help motivate companies to document their communication protocols, instead of us having to reverse them...

Anyways, I know that at least one user of IK is using this box, so we know it'll be used.

Here is a link to their API taken from their website:
https://dl.dropboxusercontent.com/s/eiihbzicmucjtlz/SCPI_commands_beta_release.pdf