Deactivate and remove the plugin with name ``name``.

def release_plugin(self, name):
        """
        Deactivate and remove the plugin with name ``name``.
        """
        plugin = self._active_plugins[name]
        if id(plugin) in self._provided_by_preset:
            self._provided_by_preset.remove(id(plugin))

        del self._active_plugins[name]
        delattr(self, name)