code: function normalizeAttrName(attrName) {
        if (!attrName) { return null }
        attrName = attrName.replace(ATTRS_PREFIX, '');
        if (CASE_SENSITIVE_ATTRIBUTES[attrName]) { attrName = CASE_SENSITIVE_ATTRIBUTES[attrName]; }
        return attrName
      }
docs: Nomalize any attribute removing the "riot-" prefix
  @param   { String } attrName - original attribute name
  @returns { String } valid html attribute name