Add intelligent Drush launcher

[jcisio]

We need a drush command that detects the current project, connects to the corresponding php container and runs drush command in the corresponding project.

[jcisio]

There is DockerGo. We can add an alias drush="DockerGo drush" if we want.

Now DocerGo always runs commands in the php71 container. It needs to be fixed, by checking the content of $DOCKER_PATH_WEB/conf/apache/vhosts.conf file to extract PHP version.