Bump Graylog Version, Fix Tarball URLs

While running with `rails 3.2.13`, and `ruby 2.0.0`, I was getting `Gemfile` conflicts.

I've bumped the `graylog-web-interface` to [`0.11.0`](https://github.com/Graylog2/graylog2-web-interface/tree/0.11.0), as well as  `graylog-server` to [`0.11.0`](https://github.com/Graylog2/graylog2-server/tree/0.11.0)