bots: Move contrib_bots to api/bots*.

This will make it convenient to include these bots in Zulip API
releases on pypi.

Fix #5009.

api/bots/help/test_help.py

@@ -0,0 +1,23 @@
+#!/usr/bin/env python
+
+from __future__ import absolute_import
+from __future__ import print_function
+
+import os
+import sys
+from six.moves import zip
+
+our_dir = os.path.dirname(os.path.abspath(__file__))
+sys.path.insert(0, os.path.normpath(os.path.join(our_dir)))
+# For dev setups, we can find the API in the repo itself.
+if os.path.exists(os.path.join(our_dir, '..')):
+    sys.path.insert(0, '..')
+from bots_test_lib import BotTestCase
+
+class TestHelpBot(BotTestCase):
+    bot_name = "help"
+
+    def test_bot(self):
+        txt = "Info on Zulip can be found here:\nhttps://github.com/zulip/zulip"
+        messages = ["", "help", "Hi, my name is abc"]
+        self.check_expected_responses(dict(list(zip(messages, len(messages)*[txt]))))