add linting for shell scripts and Dockerfiles

* 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

utils/Dockerfile

@@ -4,6 +4,8 @@ FROM ${docker_repo}/kopano_core
 RUN apt-get update && apt-get install --no-install-recommends -y \
     kopano-backup \
     kopano-migration-imap \
-    kopano-migration-pst
+    kopano-migration-pst \
+    && apt-get clean \
+    && rm -rf /var/lib/apt/lists/*
 
 CMD [ "/bin/bash" ]