code: function (callback) {
          after("helper.after", function () {
              return bluebird.resolve()
                  .then(function() {
                      if (_.isFunction(callback)) {
                          return callback();
                      }
                  })
                  .then(helper.stop.bind(helper));
          });
      }
docs: Usage:
  
  helper.after();
  
  Sets up a mocha "after" function for the describe block in a spec that
  does the relevant shutdown of core services.