As of this morning, when I gcloud app deploy, the workers no longer start.

I'm using Google AppEngine, Python Flexible Environment

[2017-08-24 19:41:31 +0000] [9] [ERROR] Exception in worker process
Traceback (most recent call last):
File "/env/lib/python3.5/site-packages/gunicorn/arbiter.py", line 578, in spawn_worker
worker.init_process()
File "/env/lib/python3.5/site-packages/gunicorn/workers/base.py", line 126, in init_process
self.load_wsgi()
File "/env/lib/python3.5/site-packages/gunicorn/workers/base.py", line 135, in load_wsgi
self.wsgi = self.app.wsgi()
File "/env/lib/python3.5/site-packages/gunicorn/app/base.py", line 67, in wsgi
self.callable = self.load()
File "/env/lib/python3.5/site-packages/gunicorn/app/wsgiapp.py", line 65, in load
return self.load_wsgiapp()
File "/env/lib/python3.5/site-packages/gunicorn/app/wsgiapp.py", line 52, in load_wsgiapp
return util.import_app(self.app_uri)
File "/env/lib/python3.5/site-packages/gunicorn/util.py", line 352, in import_app
import(module)
File "/home/vmagent/app/main.py", line 2, in
import episteme.factory
File "/home/vmagent/app/episteme/factory.py", line 25, in
import episteme.model
File "/home/vmagent/app/episteme/model/init.py", line 662, in
from . import user
File "/home/vmagent/app/episteme/model/user.py", line 563, in
from episteme.mail import EpistemeMailManager
File "/home/vmagent/app/episteme/mail/init.py", line 16, in
from google.cloud import pubsub
File "/env/lib/python3.5/site-packages/google/cloud/pubsub.py", line 17, in
from google.cloud.pubsub_v1 import PublisherClient
File "/env/lib/python3.5/site-packages/google/cloud/pubsub_v1/init.py", line 18, in
from google.cloud.pubsub_v1.publisher import Client as PublisherClient
File "/env/lib/python3.5/site-packages/google/cloud/pubsub_v1/publisher/init.py", line 17, in
from google.cloud.pubsub_v1.publisher.client import Client
File "/env/lib/python3.5/site-packages/google/cloud/pubsub_v1/publisher/client.py", line 27, in
from google.cloud.pubsub_v1.publisher.batch import thread
File "/env/lib/python3.5/site-packages/google/cloud/pubsub_v1/publisher/batch/thread.py", line 22, in
from google.cloud.pubsub_v1.publisher import exceptions
File "/env/lib/python3.5/site-packages/google/cloud/pubsub_v1/publisher/exceptions.py", line 19, in
from google.api.core.exceptions import GoogleAPICallError
ImportError: No module named 'google.api.core'