Non-deterministic unit test (test_run_in_transaction_w_timeout)

[dhermes]

The failure is:

self.assertGreater(len(called_with), 1)

Observed failures:

1. https://circleci.com/gh/GoogleCloudPlatform/google-cloud-python/1064
2. https://ci.appveyor.com/project/GoogleCloudPlatform/google-cloud-python/build/1.0.1143.master/job/x22vv8q3ftl2to1o
3. https://ci.appveyor.com/project/GoogleCloudPlatform/google-cloud-python/build/1.0.1144.master/job/awpf0vg10pknev8i
4. https://ci.appveyor.com/project/GoogleCloudPlatform/google-cloud-python/build/1.0.1158.master/job/fppo8w73x7yfup4u
5. https://ci.appveyor.com/project/GoogleCloudPlatform/google-cloud-python/build/1.0.1160.master/job/jr47sjis2tyeuu0n
6. https://ci.appveyor.com/project/GoogleCloudPlatform/google-cloud-python/build/1.0.1164.master/job/l4y5g8d787xfhrjs
7. https://ci.appveyor.com/project/GoogleCloudPlatform/google-cloud-python/build/1.0.1167.master/job/icf5aof37jq8ghnr

[dhermes]

@tseaver Can you ack this issue / give an ETA?

[dhermes]

@tseaver Bump