sometime geoip database does not return complete hashes, use this
method to provide bulletproof retrieval

stacktrace example:

/gems/geocoder-1.2.6/lib/geocoder/lookups/esri.rb:24 in "results"
/gems/geocoder-1.2.6/lib/geocoder/lookups/base.rb:47 in "search"
/gems/geocoder-1.2.6/lib/geocoder/query.rb:11 in "execute"
/gems/geocoder-1.2.6/lib/geocoder.rb:20 in "search"
/gems/geocoder-1.2.6/lib/geocoder/stores/base.rb:111 in "do_lookup"
/gems/geocoder-1.2.6/lib/geocoder/stores/active_record.rb:259 in "geocode"

The `http_client` method returns either Net::HTTP or Net::HTTP::Proxy.
The enclosing `start` block handles the proxy so there's no need to ever
use Net::HTTP::Proxy::Get.new. It's also slightly awkward to refer to
the parent object of the block (for lack of a better phrase) from within
the block.

This is not currently returned by any of the supported lookups,
but it COULD be.

It makes it easier to add a custom lookup class or filter available
services by manipulating the correct service array.

This reverts commit 196777ea.

This reverts commit 082c526d, reversing
changes made to 242a29f8.

Some regions appear to not return this in JSON

Google and Okf perform additional checks to determine if a request is
valid. It needs to be checked first if json parsing succeeded before
accessing values of it, or else an error will occur.

and format for consistency.

GeoLite2 is a free version of a product called GeoIP2. Both use the same
format.