test: add test for invalid DSA key size

Check that invalid DSA key sizes are rejected in FIPS mode.

PR-URL: https://github.com/nodejs/node/pull/3756


Reviewed-By: Fedor Indutny <fedor.indutny@gmail.com>
Reviewed-By: Shigeki Ohtsu <ohtsu@iij.ad.jp>
Reviewed-By: James M Snell <jasnell@gmail.com>