Auto-update dependencies. [(googleapis#1093)](GoogleCloudPlatform/python-docs-samples#1093)

* Auto-update dependencies.

* Fix storage notification poll sample

Change-Id: I6afbc79d15e050531555e4c8e51066996717a0f3

* Fix spanner samples

Change-Id: I40069222c60d57e8f3d3878167591af9130895cb

* Drop coverage because it's not useful

Change-Id: Iae399a7083d7866c3c7b9162d0de244fbff8b522

* Try again to fix flaky logging test

Change-Id: I6225c074701970c17c426677ef1935bb6d7e36b4

Author: dpebot

samples/snippets/requirements.txt

@@ -1,3 +1,3 @@
-google-cloud-bigquery==0.26.0
+google-cloud-bigquery==0.27.0
 google-auth-oauthlib==0.1.0
 pytz==2017.2