code: function minlength (val, min) {
    if (typeof val === 'string') {
      return isInteger(min, 10) && val.length >= parseInt(min, 10)
    } else if (Array.isArray(val)) {
      return val.length >= parseInt(min, 10)
    } else {
      return false
    }
  }
docs: minlength
  This function validate whether the minimum length.