Support multiple values for the same OSM tag

[ialokim]

I've elaborated this little code change to support a config.json file as follows:

{
    "query": {
        "tags": {
            "public_transport:version": "2",
            "operator":  [
                "Incofer",
                "Alpizar S.A."
            ]
        }
    }
}

This generated the following Overpass query:

relation
  (9.8346,-84.2418,10.0365,-83.8507)
  ["public_transport:version" = "2"]
  ["operator" ~ "Incofer|Alpizar S.A."];
(._;);
out body;

Fixes #110

[pantierra]

Looks good to me, but haven't run the code myself. Have you tried it with special characters, like Estelí?

[ialokim]

Have you tried it with special characters, like Estelí?

It should work as before, the unicode handling isn't changed by this PR. So yes, special characters should be supported as before.