fix(entity-manager): revert entity prototype test. gives false positi…

…ves in ts

src/entity-manager.js

@@ -47,14 +47,6 @@ export class EntityManager {
    * @chainable
    */
   registerEntity(EntityClass) {
-    if (!Entity.isPrototypeOf(EntityClass)) {
-      throw new Error(`
-        Trying to register non-Entity with aurelia-orm.
-        Are you using 'import *' to load your entities?
-        <http://aurelia-orm.spoonx.org/configuration.html>
-      `);
-    }
-
     this.entities[OrmMetadata.forTarget(EntityClass).fetch('resource')] = EntityClass;
 
     return this;

test/entity-manager.spec.js

@@ -38,7 +38,7 @@ describe('EntityManager', function() {
       expect(entityManager.entities).toEqual({'with-resource': WithResource});
     });
 
-    it('Should throw when register with non-Entity', function() {
+    xit('Should throw when register with non-Entity', function() {
       let entityManager = new EntityManager(new Container());
       class Wrong {}