Update moment-node.d.ts

As of verstion 2.12.0 it is possible to list all locales that have been loaded and are available to use:

moment.locales(), added this new method to type definition. 

check: 
http://momentjs.com/docs/#/i18n/getting-locale/

moment/moment-node.d.ts

@@ -325,7 +325,7 @@ declare module moment {
         locale(language: string): Moment;
         locale(reset: boolean): Moment;
         locale(): string;
-
+        locales() : string[];
         localeData(language: string): Moment;
         localeData(reset: boolean): Moment;
         localeData(): MomentLanguage;