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

meet/Dockerfile

@@ -1,5 +1,5 @@
 ARG docker_repo=zokradonh
-FROM ${docker_repo}/kopano_base
+FROM ${docker_repo}/kopano_base:latest
 
 ARG DEBIAN_FRONTEND=noninteractive
 
@@ -10,6 +10,8 @@ ARG KOPANO_MEET_VERSION=newest
 ARG KOPANO_REPOSITORY_FLAGS="trusted=yes"
 ARG RELEASE_KEY_DOWNLOAD=0
 
+SHELL ["/bin/bash", "-o", "pipefail", "-c"]
+
 # install Kopano Core and refresh ca-certificates
 RUN \
     # community download and package as apt source repository

meet/start-service.sh

@@ -21,6 +21,7 @@ fi
 # TODO use jq to modify /usr/share/kopano-kweb/www/config/kopano/meet.json
 
 sed -i s/\ *=\ */=/g /etc/kopano/kwebd.cfg
+# shellcheck disable=SC2046
 export $(grep -v '^#' /etc/kopano/kwebd.cfg | xargs -d '\n')
 # cleaning up env variables
 unset "${!KCCONF_@}"