Update Dockerfile

add supervisor & cron

Author: zacksleo

7.1/jessie/fpm/mssql/Dockerfile

@@ -40,3 +40,9 @@ RUN apt-get update && apt-get install -y \
         libpng-dev \
     && docker-php-ext-configure gd --with-freetype-dir=/usr/include/ --with-jpeg-dir=/usr/include/ \
     && docker-php-ext-install gd
+
+# prepare for using supervisor
+apt-get install -y --no-install-recommends supervisor
+
+# setup cron and logrotate
+apt-get install -y --no-install-recommends cron