* replace bash function to list docker tags with https://github.com/genuinetools/reg/
* this depends on new release in https://github.com/genuinetools/reg/issues/186 to fully function
* update docker version
* fix version.sh to also show versions from repos defined in .env
* add script to list available tags and update values in .env
* define default values for all version vars
* add previously missing containers
* use command instead of hash in update env script
* use a custom select function instead shell builtin (since it does not handle default values)
* add setup-update-tag in test.exp
* add hadolint for dockerfile linting
* add hadofile config
* add checks for dockerfiles and shellcheck into makefile
* shellcheck fixes
* add workaround so that .env can be sourced again from version.sh
* hadolint fixes
* print progress of build/run.sh
* fix check for jq in setup.sh
relates to #41 and #26
* add compose to the build image
* update readme
* fine tuning for build container
* directly pass commands to run script in build env
* fix dockerfile so that everything can be build on Docker version 17.05.0-ce, build 9f07f0e-synology
