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

commit: https://github.com/kijiproject/kiji-scoring-server/commit/719b5194152b13501e6d8142b99897763af5efd6
kiji-scoring-server: [maven-release-plugin] prepare release kiji-scoring-server-0.12.1

commit: https://github.com/kijiproject/kiji-scoring-server/commit/20ebb2fe205f9255db13e22bfeb7cd5a0cfa82ca