Feature/reorganize

[Thomas-McKanna]

This is the reorganize of the flight code according to Clay's diagram. During the process of reorganizing, I changed certain aspects of the flight code. Of note:

• The Instruction class has been rolled into the Task class (the old instructions class's sole purpose was to decode messages sent over the network into tasks, so the name Instruction was misleading)
• The Drone class now sub-classes dronekit.Vehicle (rather that containing a variable that was a dronekit.Vehicle). This simplified things. For example, the old code would have had to do drone._vehicle.rangerfinder.distance and new code can do drone.rangefinder.distance.
• The Drone class is now purely an interface to the drone. It does not calculate pid values or sleep the program. These sorts of thing were better suited for DroneController, which is where they now reside. This change will allow Tasks to be much more dynamic, but has required all Tasks to be rewritten.
• Added a task for takeoff, land, and hover (of note: movement not yet implemented, but this won't be hard)

This is a big one, but I'm hoping we can get done by the flight test this weekend.

[christopher-o-toole]

Generally you should document each file with a docstring but I'll let it slide for now given our schedule. The documentation and use of constants was a bit inconsistent in some areas as well. Other than that, the majority of the code looked alright.

[Thomas-McKanna]

Chris, I will add docstrings for each file to the Trello todo list.

[ClayMav]

• test_scripts should not exist, and its contents should be in unit_tests.
• There should be no need for an __init__.py in the root directory.
• There are no configuration parameters in the flightconfig.py, I would figure at least a few things should be configurable from flight to flight.
  I don't think theres anything I really want to nitpick in the code here.