Move Oracle artifact back into main build

[stevenschlansker]

Originally, Oracle held their driver jars so tightly that you needed to sign a license just to download them. This led us to splitting out the Oracle build so your average developer didn't have to sign a contract with Oracle just to build jdbi.

Oracle by some turn of fate has relaxed their position, and the JARs are now generally available. And, having the build float makes maintaining release docs that refer to the oracle driver harder.

Let's move it back in.