Bot quitting on Bittrex exchange

[ether-btc]

Bot quits after a time period (even in manual mode with no trades) on Bittrex exchange.

`/home/pi/zenbot/node_modules/numbro/numbro.js:1111
var parts = x.toString().split('.');
^

TypeError: Cannot read property 'toString' of undefined
at multiplier (/home/pi/zenbot/node_modules/numbro/numbro.js:1111:23)
at /home/pi/zenbot/node_modules/numbro/numbro.js:1127:22
at Array.reduce ()
at correctionFactor (/home/pi/zenbot/node_modules/numbro/numbro.js:1125:21)
at Numbro.add (/home/pi/zenbot/node_modules/numbro/numbro.js:1197:47)
at /home/pi/zenbot/commands/trade.js:391:78
at /home/pi/zenbot/lib/engine.js:192:14
at /home/pi/zenbot/extensions/exchanges/bittrex/exchange.js:113:18
at Request._callback (/home/pi/zenbot/node_modules/node.bittrex.api/node.bittrex.api.js:112:25)
at Request.self.callback (/home/pi/zenbot/node_modules/request/request.js:188:22)
at emitTwo (events.js:126:13)
at Request.emit (events.js:214:7)
at Request. (/home/pi/zenbot/node_modules/request/request.js:1171:10)
at emitOne (events.js:116:13)
at Request.emit (events.js:211:7)
at IncomingMessage. (/home/pi/zenbot/node_modules/request/request.js:1091:12)
at Object.onceWrapper (events.js:313:30)
at emitNone (events.js:111:20)
at IncomingMessage.emit (events.js:208:7)
at endReadableNT (_stream_readable.js:1056:12)
at _combinedTickCallback (internal/process/next_tick.js:138:11)
at process._tickCallback (internal/process/next_tick.js:180:9)`

[luponata]

check this: #457