Record ulimit -a in run_test output.

run_tests

@@ -1,4 +1,10 @@
-#/bin/sh
+#/usr/bin/env bash
+
+echo '----- ulimits -----'
+ulimit -a
+echo '-------------------'
+echo
+
 set -o errexit
 set -o nounset
 set -o pipefail