simulate docker environment

[veeramarni]

1. Make sure docker is installed in the laptop.
2. Switch to publish branch like devpublish
3. copy the config/staging/staging.env.sample to config/staging/staging.env and config/staging/docker-staging.env.sample to config/staging/docker-staging.env
4. install nats-server if you want to start the backend in staging mode.
5. Start the backend
6. now build docker and run docker by following command

lerna exec --scope="*frontend-server" yarn docker:build && lerna exec --scope="*frontend-server" yarn docker:run

7. frontend runs on 3010 port.