Add overloaded method.

gapi/gapi.d.ts

@@ -127,6 +127,14 @@ declare namespace gapi.auth {
 }
 
 declare namespace gapi.client {
+    /**
+    * Loads the client library interface to a particular API. If a callback is not provided, a promise is returned.
+    * @param name The name of the API to load.
+    * @param version The version of the API to load.
+    * @return promise The promise that get's resolved after the request is finished.
+    */
+    export function load(name: string, version: string): Promise<void>
+
     /**
     * Loads the client library interface to a particular API. The new API interface will be in the form gapi.client.api.collection.method.
     * @param name The name of the API to load.