Added a Docker env to run tests in a fresh env

Dockerfile

@@ -0,0 +1,14 @@
+# Run the tests in docker
+FROM php:7.4
+
+RUN apt-get update -y
+RUN apt-get install -y openssl zip unzip git iputils-ping libpng-dev libzip-dev
+RUN curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer
+
+RUN mkdir -p /home/app
+WORKDIR /home/app
+ADD . /home/app
+
+RUN composer install
+
+CMD ./vendor/bin/phpunit tests; sleep 10

docker-compose.yml

@@ -0,0 +1,13 @@
+version: '3.2'
+volumes:
+  logs:
+    driver: local
+  vendor:
+    driver: local
+services:
+  app_server:
+    restart: unless-stopped
+    build:
+      context: .
+      dockerfile: Dockerfile
+    tty: true