Specify start time

[Shima]

When running longer candle sizes (and maybe also other scenarios) it would be nice to be able to specify an exact time (and possibly date) for Gekko to go live. For example, if I run a strat on four hour candles and would like it fairly synchronized with TradeView candles so that I easier can analyze/predict the actions of Gekko, I don't want to sit around for two-three hours to press "enter" exactly when TradeView starts a new candle. I would much rather just set a start time as a switch in the console and then Gekko could run a market watcher until then so that market data is ready at the time it goes live.

Like for eample:
node gekko --config strategy.js --start 2018-02-14T04:00:00