yarn.lock to quiet dependabot :)

Bumped Mongoose version to fix CVE-2020-8244

Monitoring implmented with Prometheus, Grafana, cAdvisor and prom-client (library). Added overlay network.

Continuous Delivery implemented

Revised Gogs installation procedure

Various changes

Added mising Jenkinsfile and corrected a typo in the README.md

README.md images corrected

Implemented Jenkins, Gogs and Docker Registry (with Swarm)

Minor changes to README.me

Added staging environment

Clean up docker-compose.dev.yml

Corrected docker-compose command for dev (was down, instead of up)

MERN application dockerized in development environment

Pipeline image