fix(invokers): remove duplicate export name

BREAKING CHANGE - It is extremely doubtful than anyone was using this
or even able to use it with the previous duplicate name in place. This
does change the factory invoker decorator’s name from factory to
invokeAsFactory so that it doesn’t collide with the factory decorator
resolver.

src/invokers.js

@@ -13,7 +13,7 @@ export function invoker(value: Invoker): any {
 /**
 * Decorator: Specifies that the decorated item should be called as a factory function, rather than a constructor.
 */
-export function factory(potentialTarget?: any): any {
+export function invokeAsFactory(potentialTarget?: any): any {
   let deco = function(target) {
     metadata.define(metadata.invoker, FactoryInvoker.instance, target);
   };