Discovers the YAML format and registers it if available.

        Install YAML support via PIP::

            pip install PyYAML

def discover_yaml(self):
        """Discovers the YAML format and registers it if available.

        Install YAML support via PIP::

            pip install PyYAML
        """
        try:
            import yaml
            self.register('yaml', yaml.load, yaml.dump)
        except ImportError:
            pass