Docker bugfix

docker/php/Dockerfile

@@ -1,6 +1,11 @@
-FROM php:7-fpm
+FROM composer:latest AS composer
+FROM php:7.4-fpm
 WORKDIR "/application"
 RUN mkdir -p /application/core/Configuration
 RUN chown -R www-data:www-data /application
-RUN docker-php-ext-install mysqli
+RUN apt-get update -y && apt-get install libyaml-dev libzip-dev -y && apt-get clean && \
+    pecl install yaml && echo "extension=yaml.so" > /usr/local/etc/php/conf.d/ext-yaml.ini && \
+    docker-php-ext-enable yaml
+RUN docker-php-ext-install mysqli zip
+COPY --from=composer /usr/bin/composer /usr/bin/composer
 USER www-data