Dockerfile updates

Shorten docker build times by copying the package.json separately.

Install dependencies with npm ci

Update node to the new LTS: 14

Dockerfile

@@ -1,8 +1,9 @@
-FROM node:12-alpine
+FROM node:14-alpine
 
-COPY . /opt/app
 WORKDIR /opt/app
-RUN npm install --production
+COPY package.json package-lock.json ./
+RUN npm ci --production
+COPY . .
 
 ENV PORT=80
 EXPOSE 80