Fix minor issues with integration tests.
Fix minor issues with integration tests.

- Add report files to list for cleanup on the power consumption test.
- Start scaling test at 2 nodes so All2All works properly.
- Add env var GEOPM_KEEP_FILES to optionally save all files generated
  during the test.
- Fixed trace runtime test. Trace parsing was broken by the power
  consumption test patch.

Change-Id: Iec32c8b4996ea90609dfc753a99da6655b2ce231
Signed-off-by: Brad Geltz <e42f3ad4099980ea02f08e076efbee5cf9d4a803@intel.com>

geopm/geopm,sssylvester/geopm,geopm/geopm,sssylvester/geopm,geopm/geopm,cmcantalupo/geopm,cmcantalupo/geopm,sssylvester/geopm,geopm/geopm,geopm/geopm,sssylvester/geopm,cmcantalupo/geopm,cmcantalupo/geopm,cmcantalupo/geopm