message: replaced std::thread with std::async for dataman test trying to fix hanging problem
diff: */
  #include <numeric>
  -#include <thread>
  +#include <future>
  #include <adios2.h>
  #include <gtest/gtest.h>
  @@ -127,6 +127,7 @@ void DataManReader(Dims shape, Dims start, Dims count, size_t steps,
  adios2::Mode::Sync);
  i = dataManReader.CurrentStep();
  dataManReader.EndStep();
  + PrintData(myFloats, dataManReader.CurrentStep());
  }
  else if (status == adios2::StepStatus::NotReady)
  {
  @@ -140,18 +141,15 @@ void DataManReader(Dims shape, Dims start, Dims count, size_t steps,
  dataManReader.Close();
  }
  -TEST_F(DataManTest, WriteRead1DSingleStep)
  +TEST_F(DataManTest, WriteRead1DSubscribe)
  {
  Dims shape = {10};
  Dims start = {0};
  Dims count = {10};
  size_t steps = 100;
  std::string mode = "subscribe";
  -
  - std::thread r(DataManReader, shape, start, count, steps, mode);
  - std::thread w(DataManWriter, shape, start, count, steps, mode);
  - w.join();
  - r.join();
  + auto r = std::async(std::launch::async, DataManReader, shape, start, count, steps, mode );
  + DataManWriter(shape, start, count, steps, mode);
  }
  int main(int argc, char **argv)
  