Fix #487 Add phpcbf to run:checker Command

[alexandreelise]

Pull request related to the suggestion.

Pull Request for Issue #487 .

Summary of Changes

Change the way the tools are displayed in command line:

• Add $allowedTools array to be able to easily add or remove tools and display the list of tools added accordingly using php built-in implode function
• Add $allowedToolsString Which is the string representation of the allowed tools array helping us not having to manually change the tools to display each time
• Add sprintf to display the list of tools which I found more "clean" than a concatenation but that's suggestive. Open for your feedback.
• Add phpcbf --extensions=php because it seems that by default phpcbf tries to fix js files too which is not what we want.

Testing Instructions

Go to the root of the project.
type vendor/bin/robo run:checker phpcbf

Expected result

If there are coding standard errors most of them if not all should be automatically fixed

Actual result

the console shows a message:
The tool you required is not known. Valid tools are phpmd, phpcs, phpcpd
Since phpcbf is not added yet in RoboFile.php

Documentation Changes Required

Probably. Just adding the fact that phpcbf is available. Usually it's installed at the same time and the same folder than phpcs. But that's to be verified.

Thanks for your feedback.