Changed post_max_size in php.in to be able to upload backup files for restoration on FreePBX

Moved installation of modules to previous RUN

Install all FreePBX modules

Changed upload_max_filesize to 512M in php.ini

Changed Ubuntu version

Changed docker run command with correct image

Added gpg key for ondrej/php

Added php5.6-mbstring

Added forked message

Updated to work with Ubuntu 16.04

Remove dependency of libmyodbc

Added line to fix MySQL 5.7 compatibility

Dockerfile edited typo

start_docker-freepbx.sh added

README.md edited online with Bitbucket