Switches Docker Image to Alpine Linux to Reduce Build Time (#13)

Dockerfile

@@ -1,13 +1,13 @@
-FROM node:13.10
+FROM node:current-alpine3.12
 
 WORKDIR /app/
 
 COPY package.json /app/package.json
 
-RUN npm install
-
-RUN npm list
+RUN apk add --no-cache bash coreutils \
+ && apk add --no-cache --upgrade grep \
+ && npm install
 
 ADD entrypoint.sh /entrypoint.sh
 RUN chmod +x /entrypoint.sh
-ENTRYPOINT ["/entrypoint.sh"]
+ENTRYPOINT ["/entrypoint.sh"]