By: Michael Lynch <git@mtlynch.io>
Rename thumbnail source path parameter Match the writeThumbnails source path parameter name to the image pipeline terminology.
| Time to Start | Worker time | Duration | Time to finish | |
| Config | 2s | 9s | 9s | 11s |
| Eval | 8s | 27s | 27s | 36s |
| Build | 12s | 7m00s | 1m25s | 1m37s |
| Suite | 2s | 7m37s | 1m35s | 1m37s |