Fix issue with redis urls and unix_socket_path key error.

redis_cache/connection.py

@@ -58,7 +58,7 @@ class CacheConnectionPool(object):
 
             kwargs.update(connection_pool_class_kwargs)
 
-            if unix_socket_path is None:
+            if unix_socket_path in (None, ''):
                 kwargs.update({
                     'host': host,
                     'port': port,

redis_cache/utils.py

@@ -93,6 +93,7 @@ def parse_connection_kwargs(server, db=None, **kwargs):
 
     NOTE: taken from `redis.ConnectionPool.from_url` in redis-py
     """
+    kwargs['unix_socket_path'] = ''
     if '://' in server:
         url = server
         url_string = url