Roll src/tools/swarming_client/ 833f5ebf8..34f5f2860 (6 commits)

https://chromium.googlesource.com/infra/luci/client-py.git/+log/833f5ebf894b..34f5f28603eb

$ git log 833f5ebf8..34f5f2860 --date=short --no-merges --format='%ad %ae %s'
2018-05-16 maruel [client] trim old named caches and CIPD.
2018-05-16 sergeyberezin [swarming.py] Allow description in query-list to be optional.
2018-05-14 maruel [client] stop mocking the file system in some unit test
2018-05-14 maruel [client] fix isolateserver client file mode handling with tarred filed
2018-05-14 maruel [client] better handle tarfile created on other OSes
2018-05-04 maruel [swarming] Add new task result state NO_RESOURCE

Created with:
  roll-dep src/tools/swarming_client

Change-Id: I58e9bde586483a74c9ce4d7130f40aed04b2a869
Reviewed-on: https://chromium-review.googlesource.com/1065469Reviewed-by: Quinten Yearsley <qyearsley@chromium.org>
Commit-Queue: Marc-Antoine Ruel <maruel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#561672}

DEPS

@@ -104,7 +104,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling swarming_client
   # and whatever else without interference from each other.
-  'swarming_revision': '833f5ebf894be1e3e6d13678d5de8479bf12ff28',
+  'swarming_revision': '34f5f28603ebda484debc188fb9004db95a41451',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling ANGLE
   # and whatever else without interference from each other.