go.tools/dashboard/watcher: commit watcher rewrite

LGTM=bradfitz
R=bradfitz, alex.brainman, dvyukov
CC=golang-codereviews
https://golang.org/cl/155730043
2 files changed
tree: a38b26d96f54ad9cd6981224d1afd2bcb3bb4039
  1. app/
  2. builder/
  3. coordinator/
  4. env/
  5. updater/
  6. watcher/
  7. README