added capability to provide logger (#19)

* added capability to provide logger

Author: AlexGalichenko

CHANGELOG.MD

@@ -4,6 +4,9 @@ All notable changes to the "@qavajs/memory" will be documented in this file.
 
 Check [Keep a Changelog](http://keepachangelog.com/) for recommendations on how to structure this file.
 
+## [1.6.0]
+- :rocket: added capability to provide logger
+
 ## [1.5.1]
 - :beetle: fixed issue with non string inputs
 

index.d.ts

@@ -1,7 +1,12 @@
+declare interface Logger {
+    log(value: any): void;
+}
+
 declare type Memory = {
     register(memoryMap: Object): void;
     setValue(key: string, value: any): void;
     getValue(key: string): any;
+    setLogger(logger: Logger): void;
 }
 declare const memory: Memory;
 declare module '@qavajs/memory' {