modules now get a owned Instance

src/core/instance/module.rs

@@ -16,11 +16,11 @@ pub struct EmptyModule {
 }
 
 impl Module for EmptyModule {
-    fn init(&mut self, instance: &Instance) -> MizeResult<()> {
+    fn init(&mut self, instance: Instance) -> MizeResult<()> {
         println!("empty module fn init");
         Ok(())
     }
-    fn exit(&mut self, instance: &Instance) -> MizeResult<()> {
+    fn exit(&mut self, instance: Instance) -> MizeResult<()> {
         println!("empty module fn exit");
         Ok(())