function normalize( pts ) {
	var tmp = replace( pts, RE_VARIATION_SELECTOR, '' );
	tmp = replace( tmp, RE_ZERO_WIDTH_JOINER, '' ); // zero width joiner (ZWJ) sequences
	tmp = replace( tmp, RE_SKIN_TONES, '' );
	return replace( tmp, /\s+/g, '' );
}
Normalizes a codepoint sequence.

@private
@param {string} pts - codepoints
@returns {string} normalized string