code: function vine(str) {
  	var regex = /https:\/\/vine\.co\/v\/([a-zA-Z0-9]*)\/?/;
  	var matches = regex.exec(str);
  	return matches && matches[1];
  }
docs: Get the vine id.
  @param {string} str - the url from which you want to extract the id
  @returns {string|undefined}