This is a breaking change.

Changelog:
- Redis is now mandatory and enabled by default
- Added Sentinel, Standalone and Cluster support
- Standalone mode with sidecar is used by default
  - If no host(s) are configured, a redis sidecar is injected into the deployment
  - No extra configuration needed
  - This is intended for development and does not scale.
- Helm values have changed, see README.md:
  - `redis.host` has been renamed to `redis.hosts` and expects a list of strings with the following pattern: <localhost:6379> (needed for sentinel and cluster modes)
  - `redis.port` has been removed, see `redis.hosts`

- Unit and Integration tests now use "inject" instead of starting a server
  and using supertest.
- Add Coverage Reports and "test:dev" mode. This enables a mocha --watch
  like workflow using nodemon, as --watch does not work with esm modules.
- Reorganized and renamed files and functions

this can not only be handled on ingress level, but we need to mount the
express app also on the app root level. This basically just works out of the
box.