Add mrkdwn_in in slack test
Add mrkdwn_in in slack test

influxdb/kapacitor,titilambert/kapacitor,sputnik13/kapacitor,influxdb/kapacitor,adityacs/kapacitor,adityacs/kapacitor,influxdb/kapacitor,sputnik13/kapacitor,titilambert/kapacitor,sputnik13/kapacitor,adityacs/kapacitor,titilambert/kapacitor