Test slack integration feature on Webapp staging and redirect the notifications

[bishwaspraveen]

Description

Slack notifications from Webapp prod are currently being sent to the sde-internal channel. This shouldn't be the same for the staging server as it might create a ton of confusion. Test if this feature works as expected on the staging env and redirect the notifications accordingly.

Implementation

Tested the integration and it works perfectly.
The notifications have now been redirected to Emily's personal thread because of two reasons :

• We do not want staging environment to be sending notifications to the sde-internal channel.
• Emily is the right person to be getting notifications from the staging env since she's going to be doing all the testing on new features before they're put into production.