v1.12.0

The tiup-bench component has been moved to this standalone repo and has been rewritten by calling go-tpc/go-ycsb directly.

This release includes:

• go-tpc v1.0.9
• go-ycsb v1.0.0

Full Changelog: https://github.com/PingCAP-QE/tiup-bench/commits/v1.12.0