[cerb] relay notifications through slack with time and activity conditions

notify to slack.json

{
  "behavior":{
    "title":"Notifications to slack",
    "is_disabled":false,
    "is_private":false,
    "event":{
      "key":"event.notification.received.worker",
      "label":"New notification for me"
    },
    "nodes":[
      {
        "type":"switch",
        "title":"Between 09:00 and 23:00?",
        "nodes":[
          {
            "type":"outcome",
            "title":"Yes",
            "params":{
              "groups":[
                {
                  "any":0,
                  "conditions":[
                    {
                      "condition":"_time_of_day",
                      "oper":"between",
                      "from":"09:00",
                      "to":"23:00"
                    },
                    {
                      "condition":"assignee_last_activity_date",
                      "oper":"!is",
                      "from":"-1 hour",
                      "to":"now"
                    }
                  ]
                }
              ]
            },
            "nodes":[
              {
                "type":"action",
                "title":"Notify me on slack",
                "params":{
                  "actions":[
                    {
                      "action":"core.va.action.http_request",
                      "http_verb":"post",
                      "http_url":"https:\/\/hooks.slack.com\/services\/yourtokenhere",
                      "http_headers":"",
                      "http_body":"payload={ \"channel\": \"@niek\", \"username\": \"cerb\", \"icon_emoji\": \":cerb:\", \"attachments\":[ { \"fallback\":\"{{message}} - {{url}}\",\"color\":\"#0099CC\", \"fields\":[ { \"title\":\"New notification in cerb\", \"value\":\"{{message}} - {{url}}\", \"short\":false } ] } ] }",
                      "run_in_simulator":"1",
                      "response_placeholder":"_http_response"
                    }
                  ]
                }
              }
            ]
          }
        ]
      }
    ]
  }
}