First shot : extraction, scoring and presentation

1 / Cities extraction from CSV at server's start (only once, execution
time optimization).
2 / Parameters checking.
3 / Unique city names and state conversion from integer to string for
the Canadian cities.
4 / First idea on a scoring algorithm depending on the missing
characters length, the distance to the localisation parameters and the
population of each city.
5 / Endpoint is operational and returning a JSON format.