Create a `ce-dev command` command for executing commands on the container

[gregharvey]

The idea is this is application agnostic. It should allow for command aliases, short cuts if you will, that are made up of an execution path and a name. We should provide some defaults, such as drush for Drupal applications and console for Symfony applications, but they should be customisable and it should be possible to add others. For example the drush short cut might default to:

• /home/deploy/deploy/myproject/vendor/bin/drush
• drush

So if I execute this ce-dev command:

ce-dev command drush cr

... then ce-dev will "know" that drush us at /home/deploy/deploy/myproject/vendor/bin/drush and will execute:

/home/deploy/deploy/myproject/vendor/bin/drush cr

within the container.

I could equally provide other custom short cuts, to run my own shell script for example.

[matason]

@gregharvey @philipnorton42 Just a heads up that there is already drush present in the 2.x branch of ce-dev:

moot% ce-dev drush cache:rebuild
[success] Cache rebuild complete.