Drone Following Project #14: Updated Arduino sketch

I'm feeling better, so I went ahead and fulfilled all of my improvements for modifying the Arduino sketch, along with some new features. Here's a quick overview of the new features:

• Two publishers (Uint8 for state, and Bool for new state)
• Consistent "/Lakitu/Device" name scheme
• 3 LEDs (blue, yellow, green)
• 4 states (Landing, DronePosition, Takeoff, Calibration)

The two publishers were already explained, but why did I add a whole new state? Well, again, I was thinking ahead at the steps that need to be taken when GPS is implemented. We've taken it for granted so far that the Drone is going to translate its position from the device, however, I failed to addressed how the Drone would receive its initial distance from where the device will be. There are a few sensing and distance ways to go about this, but I worry that many of them limit the set of scenarios greatly. I currently have it in mind that you will be able to press a button to generate a GPS location for the Drone that will change as the Drone moves. Whether this method is successful or not, I feel that it's good to secure a state where the user can can safely move around and find the initial distance from the drone without the danger of it moving.

Anyways, you can can see the changes made on Github. Enjoy!