Defining Commands about easytello

[ezrafielding]

The flip command in easyTello accepts the same commands as the ones outlined in the Tello 1.3.0.0 SDK. So to flip forward for instance, you would say mydrone.flip('f'). The flip method accepts a single string which defines direction. They are 'l' for left, 'r' for right, 'f' for forward, and 'b' for backward. I do agree that we need a full list of commands in the easyTello docs, but in the mean time, the Tello 1.3.0.0 SDK notes are a good starting point.