Send notification to hermes for new comment creation

Once a new comment is created, a new entry is created under Event table to be able to sent out to hermes.

Payload keys include - `project_name` (if), `package_name` (if), `request_id` (if), `comment` (body of the comment), `commenter` (name of the user making comment) and involved_users (list of users who have made comment under a $object type.).

Any feedback or comments are welcome.

Hermes template files are at - https://github.com/shayonj/hermes/commit/acb74f4671114573f2048610f72358f38b332cc0

Cheers!