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

This reverts commit 91505f3f2ace8b26e4dae90d362563bf2faa8fbf.
Revert "[maven-release-plugin] prepare release v0.8.1-incubating"

This reverts commit fba873857133fb87cd53dc4cb0501eea1bd7edbf.