Better exceptions for failed commands in BinaryRenderer

[notFloran]

We let symfony process handle the exceptions by using mustRun method.

Example:

The command "'mjml-not-found' '-V'" failed.

Exit Code: 127(Command not found)

Working directory: /Users/floranbrutel/dev/mjml-bundle

Output:
================


Error Output:
================
sh: line 0: exec: mjml-not-found: not found
" at
/Users/floranbrutel/dev/mjml-bundle/vendor/symfony/process/Process.php:256
/Users/floranbrutel/dev/mjml-bundle/src/Renderer/BinaryRenderer.php:40
We let symfony process handle the exceptions by using mustRun method
/Users/floranbrutel/dev/mjml-bundle/src/Renderer/BinaryRenderer.php:59
/Users/floranbrutel/dev/mjml-bundle/tests/Renderer/BinaryRendererTest.php:32
.