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

This reverts commit c4746aa6fe4aaf383e69e34353114d36d1eb9ba6.
Revert "[maven-release-plugin] prepare release v1.0.0-rc7"

This reverts commit 9212b3e5bb5545ccfce242da8d89108e6fb1c464.