message: Added random load
diff: #include <adios2.h>
  #include <adios2_c.h>
  #include <chrono> // std::chrono::seconds
  +#include <stdlib.h> // rand
  #include <thread> // std::this_thread::sleep_for
  #include <gtest/gtest.h>
  @@ -49,10 +50,7 @@ void PGIndexAggregate1D(const std::string substreams)
  adios2_engine *bpWriter =
  adios2_open(ioH, fname.c_str(), adios2_mode_write);
  - if (mpiRank == 1)
  - {
  - std::this_thread::sleep_for(std::chrono::seconds(2));
  - }
  + std::this_thread::sleep_for(std::chrono::seconds(rand() % 5));
  adios2_close(bpWriter);
  bpWriter = NULL;
  