Add language support for profile API (#215)

* Add language support for profile API

* Make language optional

Author: dlackty

lib/types.ts

@@ -16,6 +16,7 @@ export type Profile = {
   userId: string;
   pictureUrl: string;
   statusMessage: string;
+  language?: string;
 };
 
 /**
@@ -499,7 +500,7 @@ export type MessageCommon = {
   quickReply?: QuickReply;
   /**
    * [Change icon and display name](https://developers.line.biz/en/docs/messaging-api/icon-nickname-switch/)
-   * 
+   *
    * When sending a message from the LINE Official Account, you can specify the `sender.name` and the `sender.iconUrl` properties in [Message objects](https://developers.line.biz/en/reference/messaging-api/#message-objects).
    */
   sender?: Sender;
@@ -1759,7 +1760,7 @@ export type Sender = {
    */
   name?: string;
   /**
-   * Icon image URL 
+   * Icon image URL
    *
    * - Max character limit: 1000
    * - URL scheme: https