Attempt upload artifacts to Sonatype OSS Nexus for Maven Central

http://yennicktrevels.com/blog/2013/10/11/automated-gradle-project-deployment-to-sonatype-oss-repository/

use a 'spongycastle' subgroup to give a useful grouping

Apparently this is legit:

https://docs.sonatype.org/display/Repository/Choosing+your+Coordinates