Update .gitlab-ci.yml: use Composer 1.10.1 since I have not tested the v2 yet.

.gitlab-ci.yml

@@ -3,9 +3,9 @@ stages:
 
 test:
   stage: test
-  image: composer:latest
+  image: composer:1.10.1
   script:
-    - composer install --prefer-dist --no-ansi --no-progress --no-suggest --no-interaction
+    - composer install --prefer-dist --no-ansi --no-progress --no-interaction
   cache:
     paths:
       - vendor/