feature: redis cluster as broker

Support new transport: redis-cluster

Basicly use redis transport code and replace the redis part into
alauda-redis-py-cluster which is a patch and waiting to be merged into
main branch.

Signed-off-by: Lei Gong <xue177125184@gmail.com>

requirements/extras/redis-cluster.txt

@@ -0,0 +1,2 @@
+redis>=2.10.3
+alauda-redis-py-cluster==1.3.4

requirements/test-ci.txt

@@ -2,5 +2,6 @@ boto
 coverage>=3.0
 coveralls
 redis
+alauda-redis-py-cluster
 PyYAML
 msgpack-python>0.2.0  # 0.2.0 dropped 2.5 support

requirements/test-ci3.txt

@@ -1,5 +1,6 @@
 coverage>=3.0
 coveralls
 redis
+alauda-redis-py-cluster
 PyYAML
 msgpack-python>0.2.0  # 0.2.0 dropped 2.5 support

setup.py

@@ -131,6 +131,7 @@ def extras(*p):
     'msgpack': extras('msgpack.txt'),
     'yaml': extras('yaml.txt'),
     'redis': extras('redis.txt'),
+    'redis-cluster': extras('redis-cluster.txt'),
     'mongodb': extras('mongodb.txt'),
     'sqs': extras('sqs.txt'),
     'couchdb': extras('couchdb.txt'),