code: function(ruleTag, tagName, displayName){
          ruleTag = ruleTag.toLowerCase();
          if(tagName && ruleTag === tagName.toLowerCase()){
              return true;
          }
          if(displayName && ruleTag === displayName.toLowerCase()){
              return true;
          }
          return false;
      }
docs: Checks if the element matches the provided tag name (if DOM node) or
  display name (if React component)
  @param  {String} ruleTag     Tag name of CSS rule
  @param  {String} tagName     Tag name of element
  @param  {String} displayName Display name of element
  @return {Bool}               Whether element matches tag query