demo flask throwing error

gistfile1.txt

docker-compose up --build
Building website
Step 1 : FROM python:2.7-slim
 ---> 035cf774b0b8
Step 2 : MAINTAINER Nick Janetakis <[email protected]>
 ---> Using cache
 ---> 0554b77eccd4
Step 3 : ENV INSTALL_PATH /snakeeyes
 ---> Using cache
 ---> 97e63342861a
Step 4 : RUN mkdir -p $INSTALL_PATH
 ---> Using cache
 ---> 36566f352b78
Step 5 : WORKDIR $INSTALL_PATH
 ---> Using cache
 ---> 8180895e656d
Step 6 : COPY requirements.txt requirements.txt
 ---> Using cache
 ---> 5765014405e2
Step 7 : RUN pip install -r requirements.txt
 ---> Using cache
 ---> 1903e35298f4
Step 8 : COPY . .
 ---> 68f4091da51e
Removing intermediate container 749a4793f732
Step 9 : CMD gunicorn -b 0.0.0.0:8000 --access-logfile - "snakeeyes.app:create_app()"
 ---> Running in 7e16effb4ad7
 ---> d5363f48440a
Removing intermediate container 7e16effb4ad7
Successfully built d5363f48440a
Recreating snakeeyes_website_1
Attaching to snakeeyes_website_1
website_1  | [2016-06-09 20:18:51 +0000] [1] [INFO] Starting gunicorn 19.4.5
website_1  | [2016-06-09 20:18:51 +0000] [1] [INFO] Listening at: http://0.0.0.0:8000 (1)
website_1  | [2016-06-09 20:18:51 +0000] [1] [INFO] Using worker: sync
website_1  | [2016-06-09 20:18:51 +0000] [9] [INFO] Booting worker with pid: 9
website_1  | [2016-06-09 20:18:58 +0000] [9] [ERROR] Error handling request /
website_1  | Traceback (most recent call last):
website_1  |   File "/usr/local/lib/python2.7/site-packages/gunicorn/workers/sync.py", line 130, in handle
website_1  |     self.handle_request(listener, req, client, addr)
website_1  |   File "/usr/local/lib/python2.7/site-packages/gunicorn/workers/sync.py", line 171, in handle_request
website_1  |     respiter = self.wsgi(environ, resp.start_response)
website_1  |   File "/usr/local/lib/python2.7/site-packages/flask/app.py", line 1836, in __call__
website_1  |     return self.wsgi_app(environ, start_response)
website_1  |   File "/usr/local/lib/python2.7/site-packages/flask/app.py", line 1820, in wsgi_app
website_1  |     response = self.make_response(self.handle_exception(e))
website_1  |   File "/usr/local/lib/python2.7/site-packages/flask/app.py", line 1403, in handle_exception
website_1  |     reraise(exc_type, exc_value, tb)
website_1  |   File "/usr/local/lib/python2.7/site-packages/flask/app.py", line 1817, in wsgi_app
website_1  |     response = self.full_dispatch_request()
website_1  |   File "/usr/local/lib/python2.7/site-packages/flask/app.py", line 1477, in full_dispatch_request
website_1  |     rv = self.handle_user_exception(e)
website_1  |   File "/usr/local/lib/python2.7/site-packages/flask/app.py", line 1381, in handle_user_exception
website_1  |     reraise(exc_type, exc_value, tb)
website_1  |   File "/usr/local/lib/python2.7/site-packages/flask/app.py", line 1475, in full_dispatch_request
website_1  |     rv = self.dispatch_request()
website_1  |   File "/usr/local/lib/python2.7/site-packages/flask/app.py", line 1461, in dispatch_request
website_1  |     return self.view_functions[rule.endpoint](**req.view_args)
website_1  |   File "/snakeeyes/snakeeyes/app.py", line 22, in index
website_1  |     return app.config['HELLO']
website_1  | KeyError: 'HELLO'
website_1  | 192.168.99.1 - - [09/Jun/2016:20:18:58 +0000] "GET / HTTP/1.1" 500 - "-" "-"