Fix docstrings in qa tests

This commit fixes the module-level docstrings for the tests and helper
modules in qa. Many of these tests were uncommented previously - this
commit ensures that every test case has at least a minimum level of
commenting.

qa/rpc-tests/proxy_test.py

@@ -2,20 +2,8 @@
 # Copyright (c) 2015-2016 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
+"""Test bitcoind with different proxy configuration.
 
-import socket
-import os
-
-from test_framework.socks5 import Socks5Configuration, Socks5Command, Socks5Server, AddressType
-from test_framework.test_framework import BitcoinTestFramework
-from test_framework.util import (
-    PORT_MIN,
-    PORT_RANGE,
-    start_nodes,
-    assert_equal,
-)
-from test_framework.netutil import test_ipv6_local
-'''
 Test plan:
 - Start bitcoind's with different proxy configurations
 - Use addnode to initiate connections
@@ -37,7 +25,20 @@ addnode connect to IPv4
 addnode connect to IPv6
 addnode connect to onion
 addnode connect to generic DNS name
-'''
+"""
+
+import socket
+import os
+
+from test_framework.socks5 import Socks5Configuration, Socks5Command, Socks5Server, AddressType
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import (
+    PORT_MIN,
+    PORT_RANGE,
+    start_nodes,
+    assert_equal,
+)
+from test_framework.netutil import test_ipv6_local
 
 RANGE_BEGIN = PORT_MIN + 2 * PORT_RANGE  # Start after p2p and rpc ports