fix: Dockerfile to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-ALPINE314-UTILLINUX-1912784

Dockerfile

@@ -1,4 +1,4 @@
-FROM python:3.7-alpine
+FROM python:3.11.0a2-alpine
 MAINTAINER Andrew Sotheran <cryptosky.user@gmail.com>
 RUN apk update && \
     apk add py-pip libc-dev gcc