code: function(apiId, stageName) {
          return new Promise(function(resolve, reject) {
              APIG.deleteStage({
                  restApiId: apiId,
                  stageName: stageName
              }, function(err) {
                  if (err) {
                      // If no such stage, then success
                      if (err.code === 404 || err.code === 'NotFoundException') {
                          return resolve(apiId);
                      }
  
                      return reject(err);
                  }
  
                  resolve(apiId);
              });
          });
      }
docs: Delete a specific stage on a specific API
  
  @return {Promise} which resolves to the API ID that the stage was deleted on