src/telegram: Add shim for Array#findIndex()

Bug:

  Array#findIndex() is unavailable in Node.js v0.x.
  Since we are deprecating Node.js v0.x already, we
  can use a shim in the mean time.

  Once we stop supporting that version range, we can
  drop the shim entirely.

tags: deprecate/node-v0.x

package.json

@@ -28,6 +28,7 @@
     "node": ">=0.12"
   },
   "dependencies": {
+    "array.prototype.findindex": "^2.0.0",
     "bl": "^1.1.2",
     "bluebird": "^3.3.4",
     "debug": "^2.2.0",

src/telegram.js

@@ -1,3 +1,6 @@
+// shims
+require('array.prototype.findindex').shim(); // for Node.js v0.x
+
 const TelegramBotWebHook = require('./telegramWebHook');
 const TelegramBotPolling = require('./telegramPolling');
 const debug = require('debug')('node-telegram-bot-api');