GitLab: also need `mysqladmin`

https://packages.debian.org/search?suite=jessie&mode=filename&searchon=contents&keywords=mysqladmin

.gitlab-ci.yml

@@ -9,7 +9,7 @@ cache:
 
 before_script:
 - apt-get update -yqq
-- 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 subversion
+- 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 subversion mariadb-client-10.0
 # Install PHP extensions
 - docker-php-ext-install mbstring mcrypt pdo_pgsql curl json intl gd xml zip bz2 opcache
 # Install Composer