Merge branch 'bug/custom_docker_image' into 'develop'

Use custom docker image with preinstalled packages.

See merge request ems/astdm/modeling.dram/dram.sys.5!22

.gitlab-ci.yml

@@ -1,9 +1,5 @@
 # vim: set ts=4 sw=4 expandtab:
-image: ubuntu
-
-before_script:
-    - DEBIAN_FRONTEND=noninteractive apt-get update --yes
-    - DEBIAN_FRONTEND=noninteractive apt-get install --yes build-essential git cmake python3 python3-dev qtbase5-dev libqwt-qt5-dev sqlite3 sqlite3-tools lcov
+image: ubuntu-dramsys
 
 stages:
     - build