function command( repl ) {
	return onCommand;

	/**
	* Prints a list of contributors.
	*
	* @private
	*/
	function onCommand() {
		repl._ostream.write( INFO ); // eslint-disable-line no-underscore-dangle
	}
}
Returns a callback to be invoked upon calling the `contributors` command.

@private
@param {REPL} repl - REPL instance
@returns {Function} callback