These .mmdb databases were created with the mmdbwriter from MaxMind [1] for
testing purposes. See the main.go file. They only contain information about
the following LBL/Berkeley network ranges:

    128.3.0.0/16
    131.243.0.0/16
    2607:f140::/32

Rebuild with:

    go build
    ./testmmdb

[1] https://github.com/maxmind/mmdbwriter
