Removed gmail code, error on successful buy.

[virtualbeck]

If you don't want to use the email notifications, you can leave out the gmail code.

I've removed the code block for gmail, but got an error:

2018/12/03 10:51:58 AM - ERROR: <class 'Exception'>
Traceback (most recent call last):
  File "app.py", line 95, in <module>
    Trader.analyse_buys()
  File "/.../src/trader.py", line 60, in analyse_buys
    self.buy_strategy(coin_pair)
  File "/.../src/trader.py", line 92, in buy_strategy
    self.buy(coin_pair, self.trade_params["buy"]["btcAmount"], current_buy_price, buy_stats)
  File "/.../src/trader.py", line 197, in buy
    self.Messenger.send_buy_gmail(buy_order_data["result"], stats)
  File ".../src/messenger.py", line 169, in send_buy_gmail
    recipient_name = self.recipient_name
AttributeError: 'Messenger' object has no attribute 'recipient_name'