implement support of unix socket for server

This feature can be used for unauthorized access to apis - e.g. for
reporting service if it is run on the same machine. Since now it becomes
recommended way for the interprocess communication, thus some options
(e.g. creating user with as-service flag) are no longer available now

setup.py

@@ -134,6 +134,7 @@ setup(
             "aiohttp_session",
             "aiohttp_security",
             "cryptography",
+            "requests-unixsocket",  # required by unix socket support
         ],
     },
 )