Issue#3 - Catch correct error in test_images command
While testing the images, a command to get the odoo status from supervisor inside the container is dispatched. If that command fails for some reason, a docker.errors.APIError is raised.
Before this: the try surrounding the call is catching an inexistent error and another error is raised, stopping the process.
After this: the try catches the correct error class and displays a more general error message.
Closes #3 (closed)