added support for telegram notifications

defaults/main.yml

@@ -1,4 +1,5 @@
 prometheus_alertmanager:
+  telegrambot: False
   args:
     "web.listen-address": "[::1]:9093"
   config:
@@ -25,7 +26,7 @@ prometheus_alertmanager:
       # resend them.
       repeat_interval: 3h
       # A default receiver
-      receiver: mail-default
+      receiver: default
       # All the above attributes are inherited by all child routes and can
       # overwritten on each.
       # The child route trees.
@@ -43,7 +44,7 @@ prometheus_alertmanager:
       equal: ['alertname', 'cluster', 'service']
     receivers:
     - name: "blackhole"
-    - name: 'mail-default'
+    - name: 'default'
       send_resolved: True
       email_configs:
       - to: 'root@localhost'