Update GitLab CI config from base template

.gitlab-ci.yml

@@ -12,9 +12,8 @@ before_script:
 - apt-get install -yqq git libmcrypt-dev libpq-dev libcurl4-gnutls-dev libicu-dev libvpx-dev libjpeg-dev libpng-dev libxpm-dev zlib1g-dev libfreetype6-dev libxml2-dev libexpat1-dev libbz2-dev libgmp3-dev libldap2-dev unixodbc-dev libsqlite3-dev libaspell-dev libsnmp-dev libpcre3-dev libtidy-dev
 # Install PHP extensions
 - docker-php-ext-install mbstring mcrypt pdo_pgsql curl json intl gd xml zip bz2 opcache
-# Install and run Composer
+# Install Composer
 - curl -sS https://getcomposer.org/installer | php
-- php composer.phar install
 # Prepare to run WP tests
 - bash bin/install-wp-tests.sh wordpress_test root '' localhost $WP_VERSION
 
@@ -27,7 +26,7 @@ services:
 variables:
   # Configure mysql environment variables (https://hub.docker.com/r/_/mysql/)
   MYSQL_DATABASE: root
-  MYSQL_ROOT_PASSWORD: ''
+  MYSQL_ALLOW_EMPTY_PASSWORD: "yes"
 
 # Run our tests
 # If Xdebug was installed you can generate a coverage report and see code coverage metrics.