Tournament Round-robin

Create a vector of rounds and their respective matches in a tournament, using the Round-robin algorithm.

Accepted: - String data type players; - number of even players; - round-trip.

Example:

``` fn main(){ let rounds = roundrobin(vec![ "Liverpool".tostring(), "Chelsea".tostring(), "M. City".tostring(), "M. United".to_string() ], false);

println!("{:#?}", rounds);

} ```

Output:

[ Round { id: 1, games: [ Game { home: "Liverpool", away: "M. United", }, Game { home: "Chelsea", away: "M. City", }, ], }, Round { id: 2, games: [ Game { home: "Liverpool", away: "M. City", }, Game { home: "M. United", away: "Chelsea", }, ], }, Round { id: 3, games: [ Game { home: "Liverpool", away: "Chelsea", }, Game { home: "M. City", away: "M. United", }, ], }, ]