TODO: Unit tests for the results.json file contents.

v2:
 - Avoid writing the nul character to mock files
 - Properly set up tmpdirs

v3:
 - Restore the resume-related changes that were lost in rebase

v4:
 - Better teardown for temporary directories
 - Build with autotools

Signed-off-by: Petri Latvala <petri.latvala@intel.com>
Reviewed-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>