Filter GA voting district shp file for county

Returns json that contains precinct name, attributes of shp file, and coordinates for a specified county for the VTD08.shp file. Includes json output for athens-clarke county.

The shp file (https://en.wikipedia.org/wiki/Shapefile) was downloaded from https://data.georgiaspatial.org/login.asp.  I'm not certain if the voting districts boundaries for Clarke county have changed since 2008, so the output coordinates may or may not be accurate for 2013.  If the boundaries have changed then hopefully we can find a more recent shp file. Possibly the folks at the Carl Vincent Institute at UGA (http://www.cviog.uga.edu/) will have it or possibly some Clarke county governmental department.

Json output is formatted like:
```
[ { "precinct" : "THOMAS N. LAY P",
    "attributes: { "ID" : 4364526,
                        "AREA" : 1.571643,
                        "PRECINCT_N" : "THOMAS N. LAYP",
                        "COUNTY_NAM" : "CLARKE",
                        ...,
    "coords": [[-83.366579,33.959114],[-83.366879,33.958914],... ]]},
  {"precinct" : "FOWLER DRIVE SC",
    "attributes" : { "ID":4364632,
                           "AREA":13.843479,
                           "PRECINCT_N":"FOWLER DRIVE SC"
                           ...},
    "coords" :  [[-83.366579,33.959114],[-83.366879,33.958914],... ]]},
 ...