Install dependencies as part of Docker build

Author: outoftime

Dockerfile

@@ -3,6 +3,11 @@ FROM node:8.10
 RUN echo '{"allow_root": true}' > /root/.bowerrc
 
 WORKDIR /app
-ADD . /app
+
+COPY package.json yarn.lock bower.json ./
+
+RUN yarn --frozen-lockfile
+
+COPY . /app
 
 EXPOSE 3000