diff --git a/.env.example b/.env.example
new file mode 100644
index 00000000..43b2d8d0
--- /dev/null
+++ b/.env.example
@@ -0,0 +1,9 @@
+APP_ENV=development
+XDEBUG_CONFIG=remote_port=9001 remote_host=172.17.0.1 remote_autostart=1 remote_log=/home/user/xdebug.log
+PHP_IDE_CONFIG=serverName=Scout
+ELASTICSEARCH_HOST=elasticsearch:9200
+DB_HOST=db
+DB_PORT=3306
+DB_DATABASE=my_database
+DB_USERNAME=root
+DB_PASSWORD=my_password
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index d47c43fe..4de95580 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -15,3 +15,8 @@ Contributions are welcome, and are accepted via pull requests. Please review the
 * Please remember that we follow [SemVer](http://semver.org/).
 
 We have [StyleCI](https://styleci.io/) setup to automatically fix any code style issues.
+
+# Running tests
+
+Run `make install` to prepare docker containers for  tests  
+Run tests `make test`
diff --git a/docker/app/Dockerfile b/docker/app/Dockerfile
index 3ec08dba..77e085aa 100644
--- a/docker/app/Dockerfile
+++ b/docker/app/Dockerfile
@@ -26,7 +26,7 @@ RUN ln -snf /usr/share/zoneinfo/${TIMEZONE} /etc/localtime && echo ${TIMEZONE} >
 RUN printf '[PHP]\ndate.timezone = "%s"\n', ${TIMEZONE} > /usr/local/etc/php/conf.d/tzone.ini
 RUN "date"
 
-RUN apt-get update && apt-get install -y libmcrypt-dev mysql-client \
+RUN apt-get update && apt-get install -y libmcrypt-dev mariadb-client \
     && docker-php-ext-install pdo_mysql
 
 FROM php as php-development