fix(core): update

ts/smartcache.classes.cachemanager.ts

@@ -1,4 +1,4 @@
-import * as plugins from './smartcache.plugins';
+import * as plugins from './smartcache.plugins.js';
 import { SmartError } from '@pushrocks/smarterror';
 
 export interface ICacheMap {
@@ -12,7 +12,7 @@ export interface ICacheMap {
 export class CacheManager {
   private _cacheMap: ICacheMap = {};
 
-  cacheExists(identifierArg): boolean {
+  cacheExists(identifierArg: string): boolean {
     if (this._cacheMap[identifierArg]) {
       return true;
     }