Create a DB management service

[kunalvirwal]

This service will basically be an extension to all the DB operations needed by Shogun.

For example, storing the Pipeline runs their successes/failures, timestamps, runtime logs, triggers, new webhook creation, new secrets creation. And all the other relevant data like the encrypted secrets themselves, webhook mappings (up for discussion).

The DB to be used is up for discussion, but Shogun have good integration with cloud databases.

[kunalvirwal]

Postgresql will be used as the DB as it will be easily integreated with RDS.