feat: notification provider (#8)

Co-authored-by: Timo Behrendt <t.behrendt@t00n.de>
Co-committed-by: Timo Behrendt <t.behrendt@t00n.de>

pkg/config/config_test.go

@@ -49,6 +49,10 @@ dns_provider:
   config:
     api_key: exampleAPIKey
     base_url: https://example.com
+notification_provider:
+  type: gotify
+  config:
+    url: https://example.com
 domains:
   - tld: example.com
     subdomains:
@@ -56,7 +60,7 @@ domains:
       - www
 check_interval: 0 0 0/6 * * * *`)
 
-		want := c.DNSProvider.Type == "ionos" && c.ExternalIPProvider.Type == "plain"
+		want := c.DNSProvider.Type == "ionos" && c.ExternalIPProvider.Type == "plain" && c.NotificationProvider.Type == "gotify"
 
 		if !want || err != nil {
 			t.Fatalf("DnsProviderName couldn't be properly loaded or unmarshaled, Load() = %v, want %v", err, want)