incident: fixed json struct tag

Signed-off-by: Alexander Trost <galexrt@googlemail.com>

incident.go

@@ -14,7 +14,7 @@ type Incident struct {
 	Name    string `json:"name"`
 	Message string `json:"message"`
 	Status  int    `json:"status"`
-	Visible int    `json"visible"`
+	Visible int    `json:"visible"`
 	Notify  bool   `json:"notify"`
 
 	ComponentID     int `json:"component_id"`
@@ -65,7 +65,7 @@ func (incident *Incident) Send(cfg *CachetMonitor) error {
 
 	incident.ID = data.ID
 	if resp.StatusCode != 200 {
-		return fmt.Errorf("Could not create/update incident!")
+		return fmt.Errorf("Could not create/update incident")
 	}
 
 	return nil