Latitude longitude filter

Latitude/Longitude filter:

This filter let you define points and a radius in order to define areas. Then, the filter could discard bid requests not belonging to those areas.

Agent config example to use the filter:

{
...
"latLongDevFilter": [{"lat": 37.123, "radius": 15.5, "long": -92.456}]
...
} 

Note that you don't need to re-create a PR from scratch to modify it after the fact. Github tracks branches so if you just push to the branch which this PR is based off, github will automatically update the PR accordingly.