docker: only log missing bridge_ip on initial fingerprint

plugins/drivers: change stats interval to duration type in proto

Documentation for preemption

Documentation fixes for affinity and spread

Co-Authored-By: preetapan <preetha@hashicorp.com>

Add Datacenters to the JobListStub struct

e2e tests for upgrade path to driver plugins

* master: (23 commits)
  tests: avoid assertion in goroutine
  spell check
  ci: run checkscripts
  tests: deflake TestRktDriver_StartWaitRecoverWaitStop
  drivers/rkt: Remove unused github.com/rkt/rkt
  drivers/rkt: allow development on non-linux
  cli: Hide `nomad docker_logger` from help output
  api: test api and structs are in sync
  goimports until make check is happy
  nil check node resources to prevent panic
  tr: use context in as select statement
  move pluginutils -> helper/pluginutils
  vet
  goimports
  gofmt
  Split hclspec
  move hclutils
  Driver tests do not use hcl2/hcl, hclspec, or hclutils
  move reattach config
  loader and singleton
  ...

Document devices

Co-Authored-By: dadgar <alex@hashicorp.com>

Merge branch 'f-driver-upgradepath-test' of https://github.com/hashicorp/nomad into f-driver-upgradepath-test

* 'f-driver-upgradepath-test' of https://github.com/hashicorp/nomad:

drivers: add docker upgrade path and e2e test

Merge branch 'f-driver-upgradepath-test' of https://github.com/hashicorp/nomad into f-driver-upgradepath-test

* 'f-driver-upgradepath-test' of https://github.com/hashicorp/nomad:
  Apply suggestions from code review

Also reorganize the docs so that scheduling has subpages in it

ci: run seperate build jobs for slower packages

Fix bug related to high cpu usage

Co-Authored-By: nickethier <ncethier@gmail.com>