kiji-scoring: [maven-release-plugin] prepare for next development iteration

commit: https://github.com/kijiproject/kiji-scoring/commit/ca5694b8d7cb64f71b0aec19a981112dbd1fa844
kiji-scoring: [maven-release-plugin] prepare release kiji-scoring-0.15.0

commit: https://github.com/kijiproject/kiji-scoring/commit/12d0f182eb49ce9c6ebc675d7acc3c4ad209e9ac