Install pcntl extension

Author: ihor-sviziev

php/7.1-fpm/Dockerfile

@@ -29,6 +29,7 @@ RUN docker-php-ext-install \
   mbstring \
   mcrypt \
   opcache \
+  pcntl \
   pdo_mysql \
   soap \
   xsl \
@@ -67,4 +68,4 @@ EXPOSE 9001
 COPY ./docker-entrypoint.sh /usr/local/bin/docker-entrypoint.sh
 
 ENTRYPOINT [ "docker-entrypoint.sh" ]
-CMD [ "php-fpm" ]
+CMD [ "php-fpm" ]