chore(deps): update dependency flaky to v3.7.0 [(#4263)](GoogleCloudPlatform/python-docs-samples#4263)

Author: renovate-bot

packages/google-cloud-containeranalysis/samples/snippets/requirements.txt

@@ -3,5 +3,5 @@ google-cloud-containeranalysis==0.3.1
 grafeas==0.4.1
 pytest==5.3.0; python_version > "3.0"
 pytest==4.6.6; python_version < "3.0"
-flaky==3.6.1
+flaky==3.7.0
 mock==4.0.2