Stage-In Unit Tests

[lukemartinlogan]

• [x] Re-run the unit test for stage-in on personal machine or Ares (or both).
• [ ] Add a unit test for directory stage-in (similar to the unit test for file stage-in).

The unit test should do the following:

1. Create a directory (/tmp/staging)
2. Use ior in file-per-process (2-4 processes) create a number of files in /tmp/staging (write mode)
3. Call ${HERMES_BUILD}/stage_in [directory] 0 0 kMinimizeIoTime to stage the entire directory
4. Use ior (read mode) to read the files in that directory (should never hit PFS)
5. Terminate Hermes using mpirun -n 1 ${HERMES_BUILD}/finalize_hermes

Note: stage-out is not required in this test, since no data is modified. Technically speaking, stage-out doesn't do anything right now since files are always synchronized to the PFS upon file close.