bots: Move contrib_bots to api/bots*.

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

Fix #5009.

bots/help/help.py

@@ -0,0 +1,18 @@
+# See readme.md for instructions on running this code.
+
+class HelpHandler(object):
+    def usage(self):
+        return '''
+            This plugin will give info about Zulip to
+            any user that types a message saying "help".
+
+            This is example code; ideally, you would flesh
+            this out for more useful help pertaining to
+            your Zulip instance.
+            '''
+
+    def handle_message(self, message, client, state_handler):
+        help_content = "Info on Zulip can be found here:\nhttps://github.com/zulip/zulip"
+        client.send_reply(message, help_content)
+
+handler_class = HelpHandler

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]))))