* update supercronic to the latest release
* update tagging for base
* fix version tag for core
* put versions for all containers into labels instead
* define vcf_ref once
* remove cache-from as caches will be invalidated early on because of passing the git ref early on
* do not rebuild when publishing
* do not rebuild when publishing
* reduce layers required for env assignment
* pull newer base images for kdav, scheduler and ssl if available
* alsp publish tag for ldap containers
* fix publishing of ssl container
* remove surplus locale configuration (should only be in base image)
update konnect
add version to ldap and ldap_demo images
* also create a tag for the ldap images
* add ldap version to compose file
* add docker pull to warm up build cache on travis
* explicitly build multi stage build stages
* make create repo script dynamic in the choice of the distribution
* 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 a kdav image
* do not install composer into the docker image
instead use a multi stage build that copies the resulting directory into the final image
* set default version in compose
resolves#54
