Update gitlab ci setup

.gitlab-ci.yml

@@ -17,12 +17,13 @@ test:7:
     image: php:7
     script:
       - vendor/bin/phpunit --coverage-text --colors=never
-
-test:hhvm:
+      
+test:7.1:
     before_script:
-      - /usr/local/bin/composer self-update
-      - composer update
-      - composer install
-    image: 51systems/docker-gitlab-ci-runner-hhvm
+      - bash build/docker_install.sh > /dev/null
+      - curl -sS https://getcomposer.org/installer | php
+      - php composer.phar update
+      - php composer.phar install
+    image: php:7.1
     script:
-      - hhvm -d hhvm.php7.all=true vendor/bin/phpunit --coverage-text --colors=never
+      - vendor/bin/phpunit --coverage-text --colors=never