Handle new subunit version 2 log files.

* modules/jenkins/files/slave_scripts/run-tox.sh: Subunit v2 log files
written by testr will output to .testrepository/$id.2. If this file is
present copy it instead of .testrepository/$id as the subunit log.

Change-Id: I3b43aa2c267773ee9d51ca369f0236e8bf9d628d
Reviewed-on: https://review.openstack.org/26417
Reviewed-by: lifeless <robertc@robertcollins.net>
Reviewed-by: James E. Blair <corvus@inaugust.com>
Approved: Jeremy Stanley <fungi@yuggoth.org>
Reviewed-by: Jeremy Stanley <fungi@yuggoth.org>
Tested-by: Jenkins
Check tests run are not less than tests found.

* modules/jenkins/files/slave_scripts/run-tox.sh: With new subunit it is
possible for the number of tests run to be greater than the number of
tests found. Change the test count check from an inequality to check to
a ran less than found check to accomodate this.

Change-Id: Ibd109196ab23c57a8bb728e8a845027cd4876801
Reviewed-on: https://review.openstack.org/26645
Reviewed-by: James E. Blair <corvus@inaugust.com>
Approved: Jeremy Stanley <fungi@yuggoth.org>
Reviewed-by: Jeremy Stanley <fungi@yuggoth.org>
Tested-by: Jenkins