Restructure contrib_bots bots to new layout.

In order to make the layout of all bots consistent, this commit
moves each bot into a folder with its name and modifies 'run.py'
so that only bots with such a structure can be executed. 'lib'
gets renamed to 'bots'.

contrib_bots/bots/wikipedia/wikipedia.py

@@ -0,0 +1,78 @@
+from __future__ import absolute_import
+from __future__ import print_function
+import requests
+import logging
+
+# See readme.md for instructions on running this code.
+
+class WikipediaHandler(object):
+    '''
+    This plugin facilitates searching Wikipedia for a
+    specific key term and returns the top article from the
+    search. It looks for messages starting with '@wikipedia'
+     or '@wiki'.
+
+    In this example, we write all Wikipedia searches into
+    the same stream that it was called from, but this code
+    could be adapted to write Wikipedia searches to some
+    kind of external issue tracker as well.
+    '''
+
+    def usage(self):
+        return '''
+            This plugin will allow users to directly search
+            Wikipedia for a specific key term and get the top
+            article that is returned from the search. Users
+            should preface searches with "@wikipedia" or
+            "@wiki".
+            '''
+
+    def triage_message(self, message, client):
+        original_content = message['content']
+
+        # This next line of code is defensive, as we
+        # never want to get into an infinite loop of posting Wikipedia
+        # searches for own Wikipedia searches!
+        if message['sender_full_name'] == 'wikipedia-bot':
+            return False
+        is_wikipedia = (original_content.startswith('@wiki') or
+                        original_content.startswith('@wikipedia'))
+
+        return is_wikipedia
+
+    def handle_message(self, message, client, state_handler):
+        query = message['content']
+
+        for prefix in ['@wikipedia', '@wiki']:
+            if query.startswith(prefix):
+                query = query[len(prefix)+1:]
+                break
+
+        query_wiki_link = ('https://en.wikipedia.org/w/api.php?action=query&'
+                           'list=search&srsearch=%s&format=json' % (query,))
+        try:
+            data = requests.get(query_wiki_link)
+        except requests.exceptions.RequestException:
+            logging.error('broken link')
+            return
+
+        if data.status_code != 200:
+            logging.error('unsuccessful data')
+            return
+
+        search_string = data.json()['query']['search'][0]['title'].replace(' ', '_')
+        url = 'https://wikipedia.org/wiki/' + search_string
+        new_content = 'For search term "' + query
+        if len(data.json()['query']['search']) == 0:
+            new_content = 'I am sorry. The search term you provided is not found :slightly_frowning_face:'
+        else:
+            new_content = new_content + '", ' + url
+
+        client.send_message(dict(
+            type=message['type'],
+            to=message['display_recipient'],
+            subject=message['subject'],
+            content=new_content,
+        ))
+
+handler_class = WikipediaHandler