matchmaker_redis compatibility with redis-py 2.4

From the redis documentation: "In addition to the changes above,
the Redis class, a subclass of StrictRedis, overrides several other
commands to provide backwards compatibility with older versions
of redis-py"

Change-Id: I76ca0d9660b086dfed74733f63450fecb89decb7
Closes-Bug: 1245447
Merge "matchmaker_redis compatibility with redis-py 2.4"