Add Python 3 classifiers.

This makes sure people know that the client is Python 3 compatible when
browsing PyPI.

Change-Id: Ie97a4de49bafc2184831ca25bc70d8af3c29d34f
refer to non-deprecated config option in help

memcache_servers was renamed to memcached_servers

Change-Id: Ia04c6655f81d5b71cee0f16a7614262efa907b62
demonstrate auth_token behavior with a simple echo service

Change-Id: I522faed9fb9d338fcaf9aeec37e04fd5078b6306
Merge "refer to non-deprecated config option in help"
Merge "Add Python 3 classifiers."
Merge "demonstrate auth_token behavior with a simple echo service"