Fixed ModuleNotFoundError: No module named 'horde'

Dockerfile

@@ -20,5 +20,6 @@ COPY ./server.py /discordbot/server.py
 COPY ./index.html /discordbot/templates/index.html
 COPY ./client.js /discordbot/static/client.js
 COPY ./style.css /discordbot/static/style.css
+COPY ./horde.py /discordbot/horde.py
 
 CMD ["python", "/discordbot/server.py"]