Fix the duration and distance values

[YuChunTsao]

Hi

I have a question about this. They seem to be given the wrong values for the duration and distance variables.

In src/controls/instructions.js on lines 55 and 56

duration: utils.format[unit](direction.distance),
distance: utils.format.duration(direction.duration)

The duration and distance values should be exchanged like this

duration: utils.format.duration(direction.duration),
distance: utils.format[unit](direction.distance)