code: function isCharVowel(char = '', includeY = true) {
    if (isEmpty(char)) return false;
    const regexp = includeY ? /[aeiouy]/ : /[aeiou]/;
    return char.toLowerCase().charAt(0).search(regexp) !== -1;
  }
docs: Tests a character and an english vowel. Returns true if the char is a vowel.
  @param  {String} char
  @param  {Boolean} [includeY=true] Optional parameter to include y as a vowel in test
  @return {Boolean}