Added common JSON encoding function.
Added common JSON encoding function.

jmaurice/gocryptotrader,snipesjr/gocryptotrader,thrasher-/gocryptotrader,snipesjr/gocryptotrader,dolanor/gocryptotrader,thrasher-/gocryptotrader,thrasher-/gocryptotrader,snipesjr/gocryptotrader,snipesjr/gocryptotrader,thrasher-/gocryptotrader,thrasher-/gocryptotrader