Run test for TelegramBot#_formatSendData() on supported Node.js versions
Run test for TelegramBot#_formatSendData() on supported Node.js versions

Bug:

  The test for `TelegramBot#_formatSendData()` is only applicable on
  newer versions of Node.js (v6+) that support passing a Buffer
  representation of the path to `fs.createReadStream()`.

Fix:

  If the runtime does NOT supports passing the Buffer argument, do
  NOT run the test on it. This is safe since we are sure that
  `fs.ReadStream.path` will never be a Buffer on the runtime being
  tested.

yagop/node-telegram-bot-api