Added geo_shape filter

Mapping Example:
  searchkick text_start: [:name], merge_mappings: true, mappings: {
    area: {
      properties: {
        boundingbox: {
          type: 'geo_shape',
          tree: "quadtree",
          precision: "1km"
        }
      }
    }
  }

  def search_data
    {
      name: name,
      boundingbox: {
        type: "envelope",
        coordinates: bounding_box_coordinates
      },
      location: [latitude, longitude]
    }
  end