security_test_image: new signer test script

Add a script so devs can run signer security tests themselves to
make sure they don't break them.

BUG=chromium-os:19543
TEST=`cbuildbot lumpy-release` passed and ran signer tests

Change-Id: I68cc3ec19616be3c91a1a14550cb38c2e6f2503d
Reviewed-on: https://gerrit.chromium.org/gerrit/34326
Commit-Ready: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
1 file changed