Remove RefreshedAt from TextWidget

This attribute is used for absolutely nothing. It doesn't need to exist.

cryptoexchanges/bittrex/widget.go

@@ -98,7 +98,6 @@ func makeMarketCurrency(name string) *mCurrency {
 // Refresh & update after interval time
 func (widget *Widget) Refresh() {
 	widget.updateSummary()
-	widget.UpdateRefreshedAt()
 	widget.display()
 }