code: function isWearable (attributes, index) {
          if (index >= attributes.inventory.length) {
              throw new InventoryIndexError(index);
          }
  
          var item = attributes.inventory[index];
  
          if (!requirements.met(attributes, item.requirements)) {
              throw new RequirementsNotMetError();
          }
  
          var slotName = item.slot;
  
          if (!slotName) {
              throw new UnequippableItemError(item.name);
          }
  
          return slotName;
      }
docs: Given index of item, returns list of possible slots
  @param {Attributes} attributes
  @param {number} index
  @return {String}