(TK-98) Add test to ensure SSLv3 isn't supported (FOR REVIEW)

Add a test to ensure that SSLv3 isn't supported by TK Jetty9
webservers by default.

I'm throwing this up now for review. However, it depends on https://github.com/puppetlabs/clj-http-client/pull/20 getting merged and clj-http-client getting released so that the dependency can be bumped to a non-SNAPSHOT version.
Is this exclusion necessary now that we've updated the `http-client` dependency?