Release 2.2-20200403045959-66ccd07

build(deps): bump flatten-maven-plugin from 1.2.1 to 1.2.2

Bumps [flatten-maven-plugin](https://github.com/mojohaus/flatten-maven-plugin) from 1.2.1 to 1.2.2.
- [Release notes](https://github.com/mojohaus/flatten-maven-plugin/releases)
- [Commits](https://github.com/mojohaus/flatten-maven-plugin/compare/flatten-maven-plugin-1.2.1...flatten-maven-plugin-1.2.2)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>