Updating author_email in all setup.py. (#3598)

Done via:

$ git grep -l author_email | \
> xargs sed -i s/jjg+google-cloud-python@google.com/googleapis-publisher@google.com/g

and manually editing `videointelligence/setup.py` and `vision/setup.py`.

Author: dhermes

packages/google-cloud-videointelligence/setup.py

@@ -27,7 +27,7 @@
 
 setup(
     author='Google Cloud Platform',
-    author_email='googleapis-packages@google.com',
+    author_email='googleapis-publisher@google.com',
     name='google-cloud-videointelligence',
     version='0.25.0',
     description='Python Client for Google Cloud Video Intelligence',