code: function () {
          var waterline = this.injector.get('Services.Waterline');
  
          return bluebird.all(
              _.map(waterline, function (collection) {
                  if (typeof collection.destroy === 'function') {
                      return bluebird.fromNode(collection.destroy.bind(collection)).then(function () {
                          if (collection.adapterDictionary.define !== 'mongo') {
                              return bluebird.fromNode(
                                  collection.adapter.define.bind(collection.adapter)
                              );
                          }
                      });
                  }
              })
          );
      }
docs: maps through all collections loaded into Services.Waterline
  and destroys them to reset testing state.
  
  Usage:
  
  beforeEach(function() {
  this.timeout(5000); // gives the system 5 seconds to do the wiping
  return waterline.start().then(function() {
  return helper.reset();
  })
  })
  
  @returns {Promise}