Avoid multiple steps

.gitlab-ci.yml

 image: debian:stable
 
-deps:
-    stage: build
-    script: apt-get update && apt-get install -y php-cli build-essential make && make dependencies
+before_script: apt-get update && apt-get install -y php-cli build-essential make && make dependencies
 
-perl:
+sytax:
     stage: test
-    script: perl -c src/tetras-back && perl -c src/configuration.pl
-
-php:
-    stage: test
-    script: for f in src/www/*.php; do php -l $f; done
+    script: perl -c src/tetras-back && perl -c src/configuration.pl && for f in src/www/*.php; do php -l $f; done