* adjust mongoose configuration
* documents more make targets in readme
* applied npm scripts convention of the client to the corresponding
  server scripts in order to be more consistent (`start` is now meant
  for local development)

* tech stack can be installed locally and will be used by app-related
  targets if available
* bumped minimal required npm version to 6.14 for server and client

* introduce a test on the server to see if user creation works (backend process <-> db only;
  still needs a test that involves the router, too)
* main server process is no connection-aware and wont start if database is not reachable
* some renaming, cause it's more descriptive
* unify quote usage

* update deps to latest and pin min node & npm version
* checkin lock files
* make server serve client to merge both into one in order to reduce complexity
* adjust CSP accordingly

src: https://github.com/aamirpinger/todo-app-client-server-kubernetes/commit/93be212a344ea910b0a13f1110975bfdfd306f3a