add contrib/jenkins.sh, for gerrit build bot

Change-Id: If8887525b0062090e9445a35e32b03e3b8e7eede
diff --git a/contrib/jenkins.sh b/contrib/jenkins.sh
new file mode 100755
index 0000000..80d6612
--- /dev/null
+++ b/contrib/jenkins.sh
@@ -0,0 +1,7 @@
+#!/bin/sh
+set -ex
+autoreconf --install --force
+./configure
+$MAKE $PARALLEL_MAKE
+$MAKE check \
+  || cat-testlogs.sh