Revert "[swarming] Add simple integration tests"
Revert "[swarming] Add simple integration tests"

This reverts commit 0dc72a0a800fa5a9e1f4dd5d7810162741a0ac64.

Reason for revert: caused race detection failures.
https://logs.chromium.org/logs/infra/buildbucket/cr-buildbucket.appspot.com/8856422888007344336/+/u/go_test_-race/stdout#L6232_59

Original change's description:
> [swarming] Add simple integration tests
>
> Bug: 1173322
> Change-Id: I28f5d112e38ac349386883fb80aaf889b2313f2c
> Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/luci-go/+/2666032
> Commit-Queue: Takuto Ikuta <71927f930fca81015e0f496c65cd126ab1a692e3@chromium.org>
> Reviewed-by: Takuto Ikuta <71927f930fca81015e0f496c65cd126ab1a692e3@chromium.org>
> Reviewed-by: Ye Kuang <yekuang@google.com>
> Auto-Submit: Junji Watanabe <aaef61ef98ffea505db831f310be2a0eb8492537@google.com>

TBR=71927f930fca81015e0f496c65cd126ab1a692e3@chromium.org,aaef61ef98ffea505db831f310be2a0eb8492537@google.com,yekuang@google.com,infra-scoped@luci-project-accounts.iam.gserviceaccount.com

Change-Id: I968255fdc4cf79e197d78834d0ad87633929e09e
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1173322
Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/luci-go/+/2665522
Auto-Submit: Junji Watanabe <aaef61ef98ffea505db831f310be2a0eb8492537@google.com>
Reviewed-by: Takuto Ikuta <71927f930fca81015e0f496c65cd126ab1a692e3@chromium.org>
Commit-Queue: Junji Watanabe <aaef61ef98ffea505db831f310be2a0eb8492537@google.com>

luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go