Remove GitLab CI testing file

.gitlab-ci.yml

-# This file is a template, and might need editing before it works on your project.
-# Select image from https://hub.docker.com/_/php/
-image: php:7.1
-
-# Select what we should cache between builds
-cache:
-  paths:
-  - vendor/
-
-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 mariadb-client-10.0
-# Install PHP extensions
-- docker-php-ext-install mbstring mcrypt mysqli curl json intl gd xml zip bz2 opcache
-# Install Composer
-- curl -sS https://getcomposer.org/installer | php
-# Install phpunit (https://docs.gitlab.com/ce/ci/examples/php.html)
-- curl --location --output /usr/local/bin/phpunit https://phar.phpunit.de/phpunit.phar
-- chmod +x /usr/local/bin/phpunit
-# Prepare to run WP tests
-- bash bin/install-wp-tests.sh wordpress_test root '' $MYSQL_PORT_3306_TCP_ADDR $WP_VERSION
-
-# Bring in any services we need http://docs.gitlab.com/ee/ci/docker/using_docker_images.html#what-is-a-service
-# See http://docs.gitlab.com/ce/ci/services/README.html for examples.
-services:
-  - mysql:5.7
-
-# Set any variables we need
-variables:
-  # Configure mysql environment variables (https://hub.docker.com/r/_/mysql/)
-  MYSQL_DATABASE: root
-  MYSQL_ALLOW_EMPTY_PASSWORD: "yes"
-
-# Run our tests
-# If Xdebug was installed you can generate a coverage report and see code coverage metrics.
-test:
-  script:
-  - /usr/local/bin/phpunit --configuration phpunit.xml --coverage-text --colors=never
\ No newline at end of file