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

This reverts commit 4ece27df4243a7b0ba2791c3c7bece5aed86d342.
Revert "[maven-release-plugin] prepare release v0.8.1-incubating"

This reverts commit bf23794a766d4f94076d2417f128f15465f25495.