Optionally clean up server connections (#444)

* Optionally clean up server connections

* move setting to pool

* fix test

* Print setting to screen

* fmt

* Fix pool_settings override in tests

src/mirrors.rs

@@ -44,6 +44,7 @@ impl MirroredClient {
             Arc::new(PoolStats::new(identifier, cfg.clone())),
             Arc::new(RwLock::new(None)),
             None,
+            true,
         );
 
         Pool::builder()