Fix typo in requirements.txt and update Dockerfile

Author: srnbckr

Dockerfile

@@ -1,11 +1,10 @@
-#docker build -t python-bitflow:latest .
 FROM python:3.7-slim
 
-
-ADD ./ /opt/python-bitflow
 WORKDIR /opt/python-bitflow
-RUN pip install --upgrade pip
-RUN pip install --upgrade setuptools
-RUN pip install --no-cache-dir -r requirments.txt
+COPY . .
+RUN pip install --no-cache-dir -r requirements.txt
+
+RUN python setup.py install
+
+ENTRYPOINT ["python-bitflow"]
 
-ENTRYPOINT [ "python3.6", "./bitflow.py" ]