.Dockerfile Base is unnecessary
```
### BASE
FROM node:8.11.3-alpine AS base
LABEL maintainer "Byungjin Park <posquit0.bj@gmail.com>"
# Set the working directory
WORKDIR /app
# Copy project specification and dependencies lock files
COPY package.json yarn.lock ./
# Install yarn
RUN apk --no-cache add yarn
```

You can see it： https://github.com/nodejs/docker-node/blob/master/8/alpine/Dockerfile