Generate Route shape data

[dellisd]

We will need to associate each Trip with a Shape. We will have to generate the shapes ourselves (for the best results) and so to avoid redundant shape generation, we will also determine which Trips share a common shape.

Shapes will be generated using OSRM's routing capabilities (where each stop along the trip will be a waypoint, along with additional "guiding" points where the minimum path taken isn't exactly what the bus route takes).