State endpoints

[dimembermatt]

See #1 for kind of an idea how to do this.

There are a couple more endpoints we need to implement:

• /reset
• /walk
• /hop
• /wiggle
• /ankles
• /demo1
• /demo2

All of these are basically the same: I send a POST request to the endpoint with the payload (essentially it's a single argument, which robot I want to touch), and it should return with result. Either success, we internally changed the state, or failure, and perhaps a reason why we failed. For example, we told robot Pinkie to /hop, but Pinkie isn't on the network.

It should modify the output.json file mentioned in #1. Specifically, the robot_state. Some sort of search is needed to find the correct robot and edit it.

A related issue regarding updating the html to send is presented in #3.