robots/coverage/diff/view.go
func deltaDisplayed(change *coverageChange) string {
	if change.baseRatio < 0 {
		return ""
	}
	return fmt.Sprintf("%.1f", (change.newRatio-change.baseRatio)*100)
}
func deltaDisplayed(change *coverageChange) string {
	if change.baseRatio < 0 {
		return ""
	}
	return fmt.Sprintf("%.1f", (change.newRatio-change.baseRatio)*100)
}
// deltaDisplayed converts a coverage ratio delta into a string value to be displayed by coverage robot