Adding support for maneuver in the directions api.


The directions API returns a useful element called maneuver which mentions the next action a traveler needs to take. 

This commit adds support to parse that. It was pretty simple since the system does parsing internally based on the field names. I just needed to add the file name.

```
"steps" : [
                ...
                     "html_instructions" : "Turn \u003cb\u003eright\u003c/b\u003e onto \u003cb\u003eWightman St\u003c/b\u003e",
                     "maneuver" : "turn-right",
                     "polyline" : {
                        "points" : "w`yuFf{yfNn@?X?X?X?zBClEGxCAj@A~BG"
                     },
                     "travel_mode" : "DRIVING"
                     ....
                  }
```

Thanks,
Pulkit