Add php-gd

docker-dev/php-fpm/Dockerfile

@@ -20,6 +20,7 @@ RUN wget -O /etc/apt/trusted.gpg.d/php.gpg https://packages.sury.org/php/apt.gpg
         php-apcu-bc \
         php7.3-cli \
         php7.3-curl \
+        php7.3-gd \
         php7.3-soap \
         php7.3-json \
         php7.3-mbstring \
@@ -54,4 +55,4 @@ USER user
 
 CMD ["/usr/sbin/php-fpm7.3", "-O" ]
 EXPOSE 9000
-WORKDIR "/application"
\ No newline at end of file
+WORKDIR "/application"