Update Dockerfile

Dockerfile

@@ -1,6 +1,6 @@
-FROM ubuntu:latest
-RUN apt update && apt install -y bash git openssh-client graphviz gcc
-RUN python -m pip install --upgrade pip setuptools wheel pyparsing pydot django-extensions django
+FROM alpine:3.12
+RUN apk update && apk add --no-cache bash git openssh python3 py3-pip graphviz gcc
+RUN python -m pip install --upgrade pip setuptools wheel pyparsing pydot pygraphviz django-extensions django
 
 COPY entrypoint.sh /entrypoint.sh
 ENTRYPOINT ["/entrypoint.sh"]