If zero tests run fail the job.
If zero tests run fail the job.

If testr ran zero tests treat that as a failing job. At least one test
should run in every Jenkins Job running testr. Failure to do that is a
job Failure.

Change-Id: I414def2db856d48f24cdc7f61437a66543e28258

open-switch/infra_puppet-jenkins,open-switch/infra_puppet-jenkins