Lower number of DB connections available per dyno in production

Author: carols10cents

src/app.rs

@@ -53,7 +53,7 @@ impl App {
             .helper_threads(if config.env == ::Env::Production {3} else {1})
             .build();
         let diesel_db_config = r2d2::Config::builder()
-            .pool_size(if config.env == ::Env::Production {50} else {1})
+            .pool_size(if config.env == ::Env::Production {30} else {1})
             .min_idle(if config.env == ::Env::Production {Some(5)} else {None})
             .helper_threads(if config.env == ::Env::Production {3} else {1})
             .build();