Add workaround for LOGSTASH-1223.

Loading "openssl" with the flatjar is super slow. For some reason it is
fast with an empty $LOAD_PATH.
- make sure we have gem deps and geoip before running tests (#615)
Merge pull request #617 from bernd/workaround-slow-openssl-load

Add workaround for slow openssl loading (LOGSTASH-1223)
Merge git://github.com/logstash/logstash