webhook: rm global sopel_instance; pass bot if bot parameter present

Functions that have a `bot` parameter (has to be called `bot`, it is not
a matter of position, but name) will receive the managing Sopel instance
as an argument. This precludes the use of `global sopel_instance`.

sopel_modules/github/webhook.py

@@ -38,12 +38,8 @@
 else:
     getargspec_ = inspect.getfullargspec
 
-# Because I'm a horrible person
-sopel_instance = None
 
 def setup_webhook(sopel):
-    global sopel_instance
-    sopel_instance = sopel
     host = sopel.config.github.webhook_host
     port = sopel.config.github.webhook_port
 
@@ -86,8 +82,6 @@ def create_table(bot, c):
 
 
 def shutdown_webhook(sopel):
-    global sopel_instance
-    sopel_instance = None
     if sopel.memory.contains('gh_webhook_server'):
         print('Stopping webhook server')
         sopel.memory['gh_webhook_server'].stop()
@@ -154,8 +148,8 @@ def stop(self):
         self.server.shutdown()
 
 
-def get_targets(repo):
-    conn = sopel_instance.db.connect()
+def get_targets(bot, repo):
+    conn = bot.db.connect()
     c = conn.cursor()
     c.execute('SELECT * FROM gh_hooks WHERE repo_name = ? AND enabled = 1', (repo.lower(), ))
     return c.fetchall()
@@ -167,7 +161,7 @@ def show_hook_info():
 
 
 @bottle.post("/webhook")
-def webhook():
+def webhook(bot):
     event = bottle.request.headers.get('X-GitHub-Event') or 'ping'
 
     try:
@@ -176,37 +170,37 @@ def webhook():
         return bottle.abort(400, 'Something went wrong!')
 
     if event == 'ping':
-        channels = get_targets(payload['repository']['full_name'])
+        channels = get_targets(bot, payload['repository']['full_name'])
         for chan in channels:
-            sopel_instance.msg(chan[0], '[{}] {}: {} (Your webhook is now enabled)'.format(
+            bot.msg(chan[0], '[{}] {}: {} (Your webhook is now enabled)'.format(
                           fmt_repo(payload['repository']['name'], chan),
                           fmt_name(payload['sender']['login'], chan),
                           payload['zen']))
         return '{"channels":' + json.dumps([chan[0] for chan in channels]) + '}'
 
     payload['event'] = event
 
-    targets = get_targets(payload['repository']['full_name'])
+    targets = get_targets(bot, payload['repository']['full_name'])
 
     for row in targets:
         messages = get_formatted_response(payload, row)
         # Write the formatted message(s) to the channel
         for message in messages:
-            sopel_instance.msg(row[0], message)
+            bot.msg(row[0], message)
 
     return '{"channels":' + json.dumps([chan[0] for chan in targets]) + '}'
 
 
 @bottle.get('/auth')
-def handle_auth_response():
+def handle_auth_response(bot):
     code = bottle.request.query.code
     state = bottle.request.query.state
 
     repo = state.split(':')[0]
     channel = state.split(':')[1]
 
-    data = {'client_id': sopel_instance.config.github.client_id,
-             'client_secret': sopel_instance.config.github.secret,
+    data = {'client_id': bot.config.github.client_id,
+             'client_secret': bot.config.github.secret,
              'code': code}
     raw = requests.post('https://github.com/login/oauth/access_token', data=data, headers={'Accept': 'application/json'})
     try:
@@ -224,7 +218,7 @@ def handle_auth_response():
             "active": True,
             "events": ["*"],
             "config": {
-                "url": sopel_instance.config.github.external_url,
+                "url": bot.config.github.external_url,
                 "content_type": "json"
             }
         }