Bump mockito-core from 3.0.0 to 3.1.0

Bumps [mockito-core](https://github.com/mockito/mockito) from 3.0.0 to 3.1.0.
- [Release notes](https://github.com/mockito/mockito/releases)
- [Commits](https://github.com/mockito/mockito/compare/v3.0.0...v3.1.0

)

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