fix(tests): rm in function type hint, not support by Python 3.5.2

tests/test_postgresql.py

@@ -38,7 +38,7 @@ def get_haproxy_conf(path: str = "/etc/haproxy/haproxy.cfg") -> dict:
     """
 
     # init configuration dictionary
-    conf: dict = {}
+    conf = {}
 
     # load configuration file
     try: