geolite.maxmind.com (Download source) no longer exists

I tried to compile this layer using the provided build script and encountered the following:

```
Step 16/20 : RUN curl http://geolite.maxmind.com/download/geoip/database/GeoLite2-City.tar.gz | tar xz
---> Running in ecab112a92fb
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0curl: (6) Could not resolve host: geolite.maxmind.com

gzip: stdin: unexpected end of file
tar: Child returned status 1
tar: Error is not recoverable: exiting now
The command '/bin/sh -c curl http://geolite.maxmind.com/download/geoip/database/GeoLite2-City.tar.gz | tar xz' returned a non-zero code: 2
```

Checking it with `curl` it seems the files are no longer available at the URL(s) provided:

```
The command '/bin/sh -c curl http://geolite.maxmind.com/download/geoip/database/GeoLite2-City.tar.gz | tar xz' returned a non-zero code: 2
ubuntu@ip-172-31-25-42:~/geoip-lambda-layer$ curl -v http://geolite.maxmind.com/download/geoip/database/GeoLite2-City.tar.gz
* Could not resolve host: geolite.maxmind.com
* Closing connection 0
curl: (6) Could not resolve host: geolite.maxmind.com
```