Revert "[maven-release-plugin] prepare for next development iteration"

This reverts commit 188f7c3f68e93b3e9347ec02e21f5943874b4741.
Revert "[maven-release-plugin] prepare release v1.0.0-rc1"

This reverts commit 6cc698fc378256fee9111f66c691ced27f54e973.
Updating versions for Spark 1.0