Bump lightgbm from 2.2.2 to 2.2.3 (#516)
Bump lightgbm from 2.2.2 to 2.2.3 (#516)

Bumps [lightgbm](https://github.com/Microsoft/LightGBM) from 2.2.2 to 2.2.3.
- [Release notes](https://github.com/Microsoft/LightGBM/releases)
- [Commits](https://github.com/Microsoft/LightGBM/compare/v2.2.2...v2.2.3)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
keras-team/autokeras,keras-team/autokeras,keras-team/autokeras