Revert "[maven-release-plugin] prepare release 7.0.0-m1-SNAPSHOT"

This reverts commit 2cdf385c4784e3d5dac8c58c82a4c605ac548ed2.
Revert "[maven-release-plugin] prepare for next development iteration"

This reverts commit e80f6beb5fa83fade3c83497f125d97ca5cb1867.
Revert "[maven-release-plugin] prepare release 7.0.0-m1-SNAPSHOT"

This reverts commit 82a27dfe2fc6397f17c486a3e189da0cad23c500.
[maven-release-plugin] prepare release 7.0.0-m1-SNAPSHOT
[maven-release-plugin] prepare for next development iteration