Update Dockerfile to use proper packaging

Dockerfile

 FROM alpine:latest
 
-RUN apk add -U python3 py3-gunicorn
-RUN mkdir /uus
-WORKDIR /uus
+COPY uus /uus
 
-COPY uus.py /uus
-COPY admin /uus/admin
-COPY requirements.txt /uus
-
-RUN pip3 install -r requirements.txt
+RUN apk add -U python3 py3-gunicorn && \
+    pip3 install /uus && \
+    rm -Rf /uus
 
 EXPOSE 8000