Allow API versioning (#85)

* add api v3 partial support.

* fix codecs in env.

* fix default codecs.

* split files.

* add session stats for api v3.

* fix API token env.

* fix null array in json.

* add CORS.

* save api version to labels.

* irgnore api token env.

* remove duplicate api version.

* move api version to settings.

client/src/api/api.ts

@@ -394,6 +394,12 @@ export interface RoomResources {
  * @interface RoomSettings
  */
 export interface RoomSettings {
+    /**
+     * 
+     * @type {number}
+     * @memberof RoomSettings
+     */
+    'api_version'?: number;
     /**
      * 
      * @type {string}