Docker & Kubernetes integration in Mango-CLI

This is the feature which wraps everything together into an easy-to-use database cluster. 

With one command, `mango start replicaset <name>` we need to boot up mango servers, mango tree, and connect with them. optionally open up a shell to send commands to it. 

Ideally the same command should also work if you're deploying on AWS. 