generateTriggerMap = function generateTriggerMap(triggers, triggerAttr) {
    var triggerMap = {};
    triggers.forEach(function (trigger) {
      var targetModal = trigger.attributes[triggerAttr].value;
      if (triggerMap[targetModal] === undefined) triggerMap[targetModal] = [];
      triggerMap[targetModal].push(trigger);
    });
    return triggerMap;
  }
Generates an object containing modals and it's
respective triggers
@param  {array} triggers     An array of all triggers
@param  {string} triggerAttr The data-attribute which triggers the module
@return {object}