Refactor GitHub Actions (#2808)

docker/Dockerfile

@@ -1,9 +1,13 @@
+ARG BASE_IMAGE_ORG
+ARG BASE_IMAGE_NAME
 ARG BASE_IMAGE_TAG
 
-FROM sanicframework/sanic-build:${BASE_IMAGE_TAG}
+FROM ${BASE_IMAGE_ORG}/${BASE_IMAGE_NAME}:${BASE_IMAGE_TAG}
 
 RUN apk update
 RUN update-ca-certificates
 
-RUN pip install sanic
+ARG SANIC_PYPI_VERSION
+
+RUN pip install -U pip && pip install sanic==${SANIC_PYPI_VERSION}
 RUN apk del build-base