Randomly choose which map builder to use

src/map_builders/mod.rs

@@ -1,7 +1,9 @@
+mod bsp_dungeon;
 mod common;
 mod simple_map;
 
 use crate::{Map, Position};
+use bsp_dungeon::BspDungeonBuilder;
 use common::*;
 use simple_map::SimpleMapBuilder;
 use specs::prelude::*;
@@ -16,6 +18,9 @@ pub trait MapBuilder {
 }
 
 pub fn random_builder(new_depth: i32) -> Box<dyn MapBuilder> {
-    // Note that until we have a second map type, this isn't even slightly random
-    Box::new(SimpleMapBuilder::new(new_depth))
+    let mut rng = rltk::RandomNumberGenerator::new();
+    match rng.roll_dice(1, 2) {
+        1 => Box::new(BspDungeonBuilder::new(new_depth)),
+        _ => Box::new(SimpleMapBuilder::new(new_depth)),
+    }
 }