Adds Oracle

Added Oracle to _data/tech.yml and logo to img/tech. I was not clear on what the 'status' field in the YAML file is intended to cover - I marked this 'Yes'.
When I go to this link, I get a 404, link not found. Did you mean [this one?](http://www.oracle.com/us/corporate/citizenship/workforce/diversity-inclusion/index.html) Or is there a pointers to more information?

As for status, it is pretty much an unused field that should onlybe yes it the company has not yet released its data but means to.