Add tests for existing timestamp behaviour
Add tests for existing timestamp behaviour

These tests document the fact that upsert_all

- never sets creation timestamps
- always sets update timestamps, on update

regardless of record_timestamps config.

yahonda/rails,yawboakye/rails,rails/rails,esparta/rails,yahonda/rails,yawboakye/rails,kddeisz/rails,esparta/rails,rails/rails,Edouard-chin/rails,kddeisz/rails,georgeclaghorn/rails,Envek/rails,kmcphillips/rails,kddeisz/rails,rails/rails,kddeisz/rails,BlakeWilliams/rails,Vasfed/rails,yawboakye/rails,lcreid/rails,Edouard-chin/rails,Edouard-chin/rails,Envek/rails,BlakeWilliams/rails,Edouard-chin/rails,esparta/rails,kmcphillips/rails,MSP-Greg/rails,kmcphillips/rails,Erol/rails,yahonda/rails,Envek/rails,lcreid/rails,MSP-Greg/rails,lcreid/rails,Envek/rails,lcreid/rails,georgeclaghorn/rails,kmcphillips/rails,rails/rails,Vasfed/rails,yahonda/rails,esparta/rails,BlakeWilliams/rails,BlakeWilliams/rails,georgeclaghorn/rails,Vasfed/rails,yawboakye/rails,MSP-Greg/rails,Erol/rails,Vasfed/rails,Erol/rails,Erol/rails,georgeclaghorn/rails,MSP-Greg/rails