Switch to Python 3.8 Alpine image as base

Dockerfile

@@ -1,20 +1,9 @@
-FROM alpine:3.6
-MAINTAINER Nat Morris <nat@nuqe.net>
+FROM python:3.8-alpine
 
 COPY requirements.txt /app/
 COPY aaisp-to-mqtt.py /app/
 WORKDIR /app
 
-RUN apk add --no-cache \
-        python \
-        ca-certificates \
-    && apk add --no-cache --virtual .build-deps \
-        py-pip \
-    && pip install -r requirements.txt \
-    && apk del --no-cache .build-deps \
-    && addgroup -g 1000 aaisp \
-    && adduser -u 1000 -G aaisp -s /bin/sh -D aaisp \
-    && chown aaisp:aaisp -R /app \
-    && echo "0 * * * * /usr/bin/python /app/aaisp-to-mqtt.py /app/config.cfg" | crontab -u aaisp -
+RUN pip install -r requirements.txt
 
-CMD ["/usr/sbin/crond", "-f", "-d", "8"]
+CMD ["/usr/bin/python", "/app/aaisp-to-mqtt.py"]