Round results down instead of up for more strictness on pass/fail. 1/1001 tests fail, this will cause tests to fail if threshold is 100%. JENKINS-19479
Added test for JENKINS-19479 - make sure that with 1 failure over 2001 tests returns unstable
Merge pull request #4 from ferrants/round_results_down

Round results down instead of up to avoid passing builds that have pass percent of 99.5 or more but not 100