Remove references to the old build system

Author: cimnine

DOCKER_HUB.md

@@ -124,31 +124,34 @@ docker-compose up -d
 
 From time to time it might become necessary to re-engineer the structure of this setup.
 Things like the `docker-compose.yml` file or your Kubernetes or OpenShift configurations have to be adjusted as a consequence.
+
 Since November 2019 each image built from this repo contains a `org.opencontainers.image.version` label.
 (The images contained labels since April 2018, although in November 2019 the labels' names changed.)
-You can check the label of your local image by running `docker inspect netboxcommunity/netbox:v2.7.1 --format "{{json .ContainerConfig.Labels}}"`.
+You can check the label of your local image by running `docker inspect netboxcommunity/netbox:v2.7.1 --format "{{json .Config.Labels}}"`.
 
 Please read [the release notes][releases] carefully when updating to a new image version.
 
 [releases]: https://github.com/netbox-community/netbox-docker/releases
 
-## Rebuilding & Publishing images
+## Rebuilding the Image
 
 `./build.sh` can be used to rebuild the Docker image. See `./build.sh --help` for more information.
 
-### Publishing Docker Images
+For more details on custom builds [consult our wiki][netbox-docker-wiki-build].
+
+[netbox-docker-wiki-build]: https://github.com/netbox-community/netbox-docker/wiki/Build
 
-New Docker images are built and published every 24h on the [Docker Build Infrastructure][docker-build-infra].
-`DOCKER_HUB.md` contains more information about the build infrastructure.
+### Pre-made Docker Images
 
-[docker-build-infra]: https://hub.docker.com/r/netboxcommunity/netbox/builds/
+New Docker images are built and published every 24h.
 
 ## Tests
 
-To run the tests coming with Netbox, use the `docker-compose.yml` file as such:
+We have a test script.
+It runs Netbox's own unit tests and ensures that all initializers work:
 
 ```bash
-docker-compose run netbox ./manage.py test
+IMAGE=netboxcommunity/netbox:latest ./test.sh
 ```
 
 ## About