Bestchange API

Library for convenient use of the bestchange api.

Example

```rust,norun extern crate bestchangeapi;

fn main() { bestchange_api::init();

let cities = bestchange_api::City::load();
let rates = bestchange_api::Rate::load();
let exchangers = bestchange_api::Exchanger::load();
let currencies = bestchange_api::Currency::load();

let city_for_id = bestchange_api::City::get_by_id(&cities, 111_u16).unwrap();
println!("{:?}", city_for_id);

let currencies_for_id208 = bestchange_api::Currency::get_by_id(&currencies, 208_u16).unwrap();
let currencies_for_id93 = bestchange_api::Currency::get_by_id(&currencies, 93_u16).unwrap();
println!("{:?}\n{:?}", currencies_for_id208, currencies_for_id93);

let rates_from_id = bestchange_api::Rate::get(&rates, 208_u16, 93_u16);

for rate in rates_from_id {
    if rate.min_sum <= 20_f32 {
        println!("{:?}", rate);
        let exchange_for_id = bestchange_api::Exchanger::get_by_id(&exchangers, rate.exchange_id).unwrap();
        println!("{:?}", exchange_for_id);
    }
}

}

```