Update jenkins-test-harness to 2.67
Update jenkins-test-harness to 2.67

This fixes some random test fails which were caused because
waitForCompletion returned early sometimes. It seems this was fixed in
2.63 by jenkinsci/jenkins-test-harness#210

jenkinsci/lockable-resources-plugin,jenkinsci/lockable-resources-plugin,jenkinsci/lockable-resources-plugin