chore(deps): update dependency pytest to v5.4.3 [(#4279)](#4279)

* chore(deps): update dependency pytest to v5.4.3

* specify pytest for python 2 in appengine

Co-authored-by: Leah Cole <[email protected]>

Author: renovate-bot

bigquery-datatransfer/snippets/requirements-test.txt

@@ -1,2 +1,2 @@
-pytest==5.3.2
+pytest==5.4.3
 mock==3.0.5