Merge branch '33-sometimes-pipeline-fails-on-install-zip-unzip-packages' into 'develop'

BUGFIX: Remove failing package installation of 'zip'

Closes #33

See merge request !34

.gitlab-ci.yml

@@ -6,7 +6,7 @@ cache:
     - vendor/
 
 before_script:
-  - apt-get update; apt-get install -y zip unzip
+  - apt-get update; apt-get install -y unzip
   - composer install --optimize-autoloader --no-interaction --no-ansi --prefer-dist
 
 lint:coding-guideline: