Add simple lucicfg configuration for art.

Notable changes:

  * Removes "luci-migration@appspot.gserviceaccount.com" group as
    Buildbucket Writers.
  * Removes "vpython:native-python-wrapper" from swarming_tags in
    builders (this has not had any functionality for a couple years
    at this point).
  * Replaces deprecated luci-notify "on_change" and "on_failure"
    settings with "on_new_status [FAILURE INFRA_FAILURE]".
  * Uses v2 bucket names in luci-scheduler.

The new configs will not be active until we change projects.cfg to
specify the new 'generated' folder.

Change-Id: I7a87a2ceb640af4cdb466d80ed4e03c1d5834f43
12 files changed