feat(Composer) Adding php extension

 * Added php extension gd.

Dockerfile

@@ -4,13 +4,19 @@ RUN apk update \
 && apk add --no-cache --virtual .build-dependencies zip zlib-dev libzip-dev libpng-dev \
 && php -r "readfile('https://getcomposer.org/installer');" | php -- --install-dir=/usr/local/bin --filename=composer \
 && apk del .build-dependencies \
-&& docker-php-ext-install sockets bcmath gd \
-&& apk add --no-cache git
+&& docker-php-ext-install sockets bcmath \
+&& apk add --no-cache git \
+&& apk add --no-cache zip libzip-dev \
+&& docker-php-ext-configure zip \
+&& docker-php-ext-install zip \
+&& apk add --no-cache libpng libpng-dev \
+&& docker-php-ext-install gd \
+&& apk del libpng-dev
 
 COPY ./custom.ini /usr/local/etc/php/conf.d/
 
 WORKDIR /app
 
 RUN composer self-update 2.0.14
 
-ENTRYPOINT ["composer"]
+ENTRYPOINT ["composer"]