Merge branch 'feature/image_name_env' into 'master'

Feature: image name env

See merge request jupyter/clb-jupyter-nb-images!6

.gitlab-ci.yml

 variables:
   docker_registry_user: "robot$$gitlab"
-  docker_image_tag: "1.2"
+  docker_image_tag: "1.3"
 
 stages:
   - build

base/Dockerfile

@@ -7,7 +7,8 @@ ENV GIT_COMMITTER_NAME=platform@humanbrainproject.eu \
     MPLBACKEND=Agg \
     SDAHOME=/opt/app-root/lib/sda_flex \
     MPICC=/usr/lib64/mpich/bin/mpicc \
-    XDG_CACHE_HOME=/tmp/cache/
+    XDG_CACHE_HOME=/tmp/cache/ \
+    LAB_IMAGE_NAME=EBRAINS_EXPERIMENTAL
 
 USER root