revert(RouterStore): Routes objects are now plain observable object a…

…gain

Revert the breaking change introduced by c60fd24 . That change made all the routes object to
be @observable.ref, but I don't feel comfortable with that. Probably other users can inject things
into the @observable routes and observe those.

src/modules/RouterStore.js

@@ -3,14 +3,13 @@ import transitionPath from 'router5.transition-path';
 
 class RouterStore {
 
-  @observable.ref route = null;
-  @observable.ref previousRoute = null;
-  @observable.ref transitionRoute = null;
+  @observable route = null;
+  @observable previousRoute = null;
+  @observable transitionRoute = null;
   @observable transitionError = null;
   @observable intersectionNode = '';
   @observable toActivate = [];
   @observable toDeactivate = [];
-
   // @observable currentView;
 
   router = null;