v0.5
added unit alert function.
if you setup 100 unit. and current price is around 1500( 1450~1550 ). then you will get alert when the price hit 1400 or 1600.
basically every 100 unit price
( ex, 100, 200, 300, .... 1400, 1500, 1600 ... ) become alert-price. except last alerted price ( 1500 ).