Fix typo in comment
I think it is a typo in comment of Alert.ResolvedAt .
@@ -93,7 +93,7 @@ func (a *Alert) Resolved() bool {
return a.ResolvedAt(time.Now())
}
-// ResolvedAt returns true off the activity interval ended before
+// ResolvedAt returns true iff the activity interval ended before
// the given timestamp.
func (a *Alert) ResolvedAt(ts time.Time) bool {
if a.EndsAt.IsZero() {
