Query GPS Coordinates within a Radius using KnexJS, Postgres and the PostGIS Extension

In this lesson we'll show how to enable the PostGIS extension on RDS. We'll then walk through using Knex to create a table to store gps coordinates. Then we'll construct queries for saving, updating, and querying for coordinates within a radius. Finally we'll use knex-postgis plugin for Knex to generate queries from helper functions.