Install node, npm, gulp and bower to the workspace container

- Add “Change the PHP-CLI Version”
- Add “Install PHP Extensions”

Develop

the workspace container is based from Ubuntu 16.04
it includes PHP-CLI 7 - Git - cURL and Vim for now

preparing to add php cli as part of the workspace container

Replace docker-compose rm with down command.

Add memcached support for PHP 5.5 & 5.6

Because there's some difference in installing some libraries
between PHP 5 and PHP 7. There must be multiple php dockerfiles.
For that I created 3 docker files each of a different version,
this will make it easy for the users to switch between the PHP
version by just editing the docker-compose file and not touching
the dockerfiles.

Memcached support