CommitIssue and StyleIssue classes have different string
representations, which are handled by type-specific print() calls in the
code that handles the issues. This requires the user to know which type
of issue it is dealing with. Simplify that by moving the string
representation logic to a __str__() method.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>