Add a threshold based golint test case

This lets some golint errors in, but fails if you're over a certain
threshold. The current threshold of 15% (of LOC) is arbitrary and
subject to change. The algorithm should be extended to check a range of
commits, although it's unclear how to detect what range of commits make
up a patch set.

test.sh

@@ -31,3 +31,4 @@ fi
 if env | grep -q -e '^JENKINS_URL=' -e '^BUILD_TAG=jenkins'; then
 	./test/test-omv.sh
 fi
+./test/test-golint.sh	# test last, because this test is somewhat arbitrary