Create OCIDCellArea #348

- Create OCIDCellArea table/model
- Change update_lac to accept arbitrary models
- Change enqueue/dequeue LACs to accept arbitrary pipelines (not presently used)
- Populate with LACs on OCID import
- Add tests for OCIDCellArea Model
- Update OCIDCell import tests to test for the presence of OCIDCellArea entries after import

@hannosch 
Much better, but this might grow out of bounds. Latitude should be in between the Web Mercator bounds of +/- 85.051, defined in data.validation MAX_LAT/MIN_LAT. So something like:
```
result = lat + (distance/111111.0)
if result > MAX_LAT:
    result = MAX_LAT
elif result < MIN_LAT:
    result = MIN_LAT
return result
```
Longitude could actually wrap around from +180.0 to -180.0 or the other way around. But for the bounding box purpose we want to just cap it at the max/min value as well. Otherwise we end up with a bounding box that suddenly spans almost the entire globe. So similar to above, with +/- 180.0 as the bounds.