Add TelegramBot#getChat() method

Notes:

  Merge branch 'master' of https://github.com/serhiidmytruk/node-telegram-bot-api into pr/144

References:

  * PR #144: https://github.com/yagop/node-telegram-bot-api/pull/144

README.md

@@ -60,6 +60,7 @@ TelegramBot
     * [new TelegramBot(token, [options])](#new_TelegramBot_new)
     * [.stopPolling()](#TelegramBot+stopPolling) ⇒ <code>Promise</code>
     * [.getMe()](#TelegramBot+getMe) ⇒ <code>Promise</code>
+    * [.getChat()](#TelegramBot+getChat) ⇒ <code>Promise</code>
     * [.setWebHook(url, [cert])](#TelegramBot+setWebHook)
     * [.getUpdates([timeout], [limit], [offset])](#TelegramBot+getUpdates) ⇒ <code>Promise</code>
     * [.sendMessage(chatId, text, [options])](#TelegramBot+sendMessage) ⇒ <code>Promise</code>
@@ -119,6 +120,15 @@ Returns basic information about the bot in form of a `User` object.
 
 **Kind**: instance method of <code>[TelegramBot](#TelegramBot)</code>  
 **See**: https://core.telegram.org/bots/api#getme  
+<a name="TelegramBot+getChat"></a>
+
+### telegramBot.getChat() ⇒ <code>Promise</code>
+Use this method to get up to date information about the chat
+(current name of the user for one-on-one conversations, current
+username of a user, group or channel, etc.).
+
+**Kind**: instance method of <code>[TelegramBot](#TelegramBot)</code>  
+**See**: https://core.telegram.org/bots/api#getchat  
 <a name="TelegramBot+setWebHook"></a>
 
 ### telegramBot.setWebHook(url, [cert])

src/telegram.js

@@ -205,6 +205,21 @@ class TelegramBot extends EventEmitter {
     return this._request(_path);
   }
 
+  /**
+   * Use this method to get up to date information about the chat
+   * (current name of the user for one-on-one conversations, current
+   * username of a user, group or channel, etc.).
+   * @return {Promise}
+   * @see https://core.telegram.org/bots/api#getchat
+   */
+  getChat(chatId) {
+    const form = {
+      chat_id: chatId
+    };
+
+    return this._request('getChat', {form: form});
+  }
+
   /**
    * Specify an url to receive incoming updates via an outgoing webHook.
    * @param {String} url URL where Telegram will make HTTP Post. Leave empty to

test/index.js

@@ -131,6 +131,15 @@ describe('Telegram', function telegramSuite() {
     });
   });
 
+  describe('#getChat', function getMeSuite() {
+    it('should return an User object', function test() {
+      const bot = new Telegram(TOKEN);
+      return bot.getChat(USERID).then(resp => {
+        assert.ok(is.object(resp));
+      });
+    });
+  });
+
   describe('#getUpdates', function getUpdatesSuite() {
     it('should return an Array', function test() {
       const bot = new Telegram(TOKEN);