Replace redis with raft + badgerDB

[alphadose]

Redis is used as a central registry server which is an unneeded dependency.

Using Raft consensus with BadgerDB as a storage mechanism, we can maintain replicated states across all nodes.

Hence, we eliminate Redis as a dependency making the deployment of gasper much more simpler.

[alphadose]

Implementation of raft + badgerDB consensus https://yusufs.medium.com/creating-distributed-kv-database-by-implementing-raft-consensus-using-golang-d0884eef2e28

[alphadose]

Raft -> https://raft.github.io/
BadgerDB -> https://github.com/dgraph-io/badger