generateTriggerMap = (triggers, triggerAttr) => {
    const triggerMap = []

    triggers.forEach(trigger => {
      const targetModal = trigger.attributes[triggerAttr].value
      if (triggerMap[targetModal] === undefined) triggerMap[targetModal] = []
      triggerMap[targetModal].push(trigger)
    })

    return triggerMap
  }
Generates an associative array of 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 {array}