client.py amelioration

[ghost]

Hello,
I think it will be better in client.py to put on the line 21:
TIMEOUT = (5.0, None)
Like that there are a timeout of 5 seconds for the connection and None for the answer
I have made too a modification which add the possibility to make postonly order:
on line 56 change by it:
def place_order(self, amount, price, side, ord_type, symbol='btcusd', exchan
ge='bitfinex', postonly=False):
and after the line 76 add:
"is_postonly": postonly
If you can commit this amelioration it will be great.
Thanks.