Set pycord user-agent (#241)

Author: typpo

discord/http.py

@@ -181,7 +181,7 @@ def __init__(
         self.proxy_auth: Optional[aiohttp.BasicAuth] = proxy_auth
         self.use_clock: bool = not unsync_clock
 
-        user_agent = 'DiscordBot (https://github.com/Rapptz/discord.py {0}) Python/{1[0]}.{1[1]} aiohttp/{2}'
+        user_agent = 'DiscordBot (https://github.com/Pycord-Development/pycord {0}) Python/{1[0]}.{1[1]} aiohttp/{2}'
         self.user_agent: str = user_agent.format(__version__, sys.version_info, aiohttp.__version__)
 
     def recreate(self) -> None: