Too hard, I'd rather reimplement this in Go

The following revision refers to this bug:
  https://chromium.googlesource.com/infra/infra/+/99fa41f5395f64cff4ac2de348e79cf49a7ce66b

commit 99fa41f5395f64cff4ac2de348e79cf49a7ce66b
Author: Nodir Turakulov <nodir@google.com>
Date: Thu May 17 15:12:07 2018

[buildbucket] add buildtags.py

Move all build tags related functions and globals to buildtags.py.
Update the rest of the code.

Pure refactoring. No functional changes.

Bug: 840853
Change-Id: I63e90eebfd503cc00070e887e9bd1b3253df1035
Reviewed-on: https://chromium-review.googlesource.com/1062498
Commit-Queue: Nodir Turakulov <nodir@chromium.org>
Reviewed-by: Vadim Shtayura <vadimsh@chromium.org>

[modify] https://crrev.com/99fa41f5395f64cff4ac2de348e79cf49a7ce66b/appengine/cr-buildbucket/swarming/swarming.py
[modify] https://crrev.com/99fa41f5395f64cff4ac2de348e79cf49a7ce66b/appengine/cr-buildbucket/test/service_test.py
[modify] https://crrev.com/99fa41f5395f64cff4ac2de348e79cf49a7ce66b/appengine/cr-buildbucket/v2/api.py
[add] https://crrev.com/99fa41f5395f64cff4ac2de348e79cf49a7ce66b/appengine/cr-buildbucket/test/buildtags_test.py
[modify] https://crrev.com/99fa41f5395f64cff4ac2de348e79cf49a7ce66b/appengine/cr-buildbucket/v2/test/api_test.py
[modify] https://crrev.com/99fa41f5395f64cff4ac2de348e79cf49a7ce66b/appengine/cr-buildbucket/service.py
[modify] https://crrev.com/99fa41f5395f64cff4ac2de348e79cf49a7ce66b/appengine/cr-buildbucket/metrics.py
[add] https://crrev.com/99fa41f5395f64cff4ac2de348e79cf49a7ce66b/appengine/cr-buildbucket/buildtags.py
[modify] https://crrev.com/99fa41f5395f64cff4ac2de348e79cf49a7ce66b/appengine/cr-buildbucket/v2/builds.py
[modify] https://crrev.com/99fa41f5395f64cff4ac2de348e79cf49a7ce66b/appengine/cr-buildbucket/swarming/test/swarming_test.py
[modify] https://crrev.com/99fa41f5395f64cff4ac2de348e79cf49a7ce66b/appengine/cr-buildbucket/model.py

The following revision refers to this bug:
  https://chromium.googlesource.com/infra/infra/+/869f21e4cdbc2bf99b4ed2c0b51b5cbecda26ece

commit 869f21e4cdbc2bf99b4ed2c0b51b5cbecda26ece
Author: Nodir Turakulov <nodir@google.com>
Date: Wed Jun 20 23:46:01 2018

[buildbucket] Move parse_identity from service.py to user.py

Bug:  854484 , 840853
Change-Id: I42a64c6d163bec3bce86ec0d4dc829fda0b5d261
Reviewed-on: https://chromium-review.googlesource.com/1108508
Commit-Queue: Nodir Turakulov <nodir@chromium.org>
Reviewed-by: Vadim Shtayura <vadimsh@chromium.org>

[modify] https://crrev.com/869f21e4cdbc2bf99b4ed2c0b51b5cbecda26ece/appengine/cr-buildbucket/service.py
[modify] https://crrev.com/869f21e4cdbc2bf99b4ed2c0b51b5cbecda26ece/appengine/cr-buildbucket/user.py
[modify] https://crrev.com/869f21e4cdbc2bf99b4ed2c0b51b5cbecda26ece/appengine/cr-buildbucket/test/user_test.py

The following revision refers to this bug:
  https://chromium.googlesource.com/infra/infra/+/8c3bc760c43930c867638648281adf8cf22ceb43

commit 8c3bc760c43930c867638648281adf8cf22ceb43
Author: Nodir Turakulov <nodir@google.com>
Date: Thu Jun 21 00:49:01 2018

[buildbucket] Add search.py

Move search-related code from monolithic service.py and model.py to search.py,
including two search implementations and TagIndex data models.
No functional changes.

Bug:  854484 , 840853
Change-Id: If83db1b82c82ed9d4fa84d1d67da42974f579105
Reviewed-on: https://chromium-review.googlesource.com/1108566
Commit-Queue: Nodir Turakulov <nodir@chromium.org>
Reviewed-by: Vadim Shtayura <vadimsh@chromium.org>

[modify] https://crrev.com/8c3bc760c43930c867638648281adf8cf22ceb43/appengine/cr-buildbucket/handlers.py
[add] https://crrev.com/8c3bc760c43930c867638648281adf8cf22ceb43/appengine/cr-buildbucket/search.py
[modify] https://crrev.com/8c3bc760c43930c867638648281adf8cf22ceb43/appengine/cr-buildbucket/test/handlers_test.py
[modify] https://crrev.com/8c3bc760c43930c867638648281adf8cf22ceb43/appengine/cr-buildbucket/test/service_test.py
[modify] https://crrev.com/8c3bc760c43930c867638648281adf8cf22ceb43/appengine/cr-buildbucket/v2/api.py
[modify] https://crrev.com/8c3bc760c43930c867638648281adf8cf22ceb43/appengine/cr-buildbucket/test/api_test.py
[modify] https://crrev.com/8c3bc760c43930c867638648281adf8cf22ceb43/appengine/cr-buildbucket/v2/test/api_test.py
[modify] https://crrev.com/8c3bc760c43930c867638648281adf8cf22ceb43/appengine/cr-buildbucket/service.py
[modify] https://crrev.com/8c3bc760c43930c867638648281adf8cf22ceb43/appengine/cr-buildbucket/test/model_test.py
[modify] https://crrev.com/8c3bc760c43930c867638648281adf8cf22ceb43/appengine/cr-buildbucket/api.py
[add] https://crrev.com/8c3bc760c43930c867638648281adf8cf22ceb43/appengine/cr-buildbucket/test/search_test.py
[modify] https://crrev.com/8c3bc760c43930c867638648281adf8cf22ceb43/appengine/cr-buildbucket/model.py

The following revision refers to this bug:
  https://chromium.googlesource.com/infra/infra/+/5895a4c112dfe8009f3d0b210abfa4061c1fa3a5

commit 5895a4c112dfe8009f3d0b210abfa4061c1fa3a5
Author: Nodir Turakulov <nodir@google.com>
Date: Wed Jun 27 18:46:33 2018

[buildbucket] Add creation.py

Extract all build creation code from service.py to creation.py.
Move tests too.

This is pure refactoring.

Bug: 840853
Change-Id: I0326bad9d257e1f738ff6251cfac4c25cfc0e23d
Reviewed-on: https://chromium-review.googlesource.com/1115876
Reviewed-by: Vadim Shtayura <vadimsh@chromium.org>
Commit-Queue: Nodir Turakulov <nodir@chromium.org>

[modify] https://crrev.com/5895a4c112dfe8009f3d0b210abfa4061c1fa3a5/appengine/cr-buildbucket/errors.py
[modify] https://crrev.com/5895a4c112dfe8009f3d0b210abfa4061c1fa3a5/appengine/cr-buildbucket/api.py
[modify] https://crrev.com/5895a4c112dfe8009f3d0b210abfa4061c1fa3a5/appengine/cr-buildbucket/test/api_test.py
[add] https://crrev.com/5895a4c112dfe8009f3d0b210abfa4061c1fa3a5/appengine/cr-buildbucket/test/creation_test.py
[modify] https://crrev.com/5895a4c112dfe8009f3d0b210abfa4061c1fa3a5/appengine/cr-buildbucket/service.py
[modify] https://crrev.com/5895a4c112dfe8009f3d0b210abfa4061c1fa3a5/appengine/cr-buildbucket/test/errors_test.py
[add] https://crrev.com/5895a4c112dfe8009f3d0b210abfa4061c1fa3a5/appengine/cr-buildbucket/creation.py
[modify] https://crrev.com/5895a4c112dfe8009f3d0b210abfa4061c1fa3a5/appengine/cr-buildbucket/test/service_test.py