Add travis-ci, hopefully without spamming the BC folks

Pretty sure BouncyCastle needs OpenJDK to build and run tests

I don't know how to register the unsigned JCE provider on Oracle JDK,
OpenJDK doesn't seem to check.

try to make travis output clearer

http://stackoverflow.com/a/17942820/438886
Hopefully fix test by installing BC provider

https://travis-ci.org/rtyley/spongycastle/builds/17031595