Alter Dockerfiles layers ordering to cache deps

Lab 1/Dockerfile

@@ -1,8 +1,8 @@
 FROM node:9.4.0-alpine
-COPY app.js .
 COPY package.json .
 RUN npm install &&\
     apk update &&\
     apk upgrade
+COPY app.js .
 EXPOSE  8080
 CMD node app.js

Lab 2/Dockerfile

@@ -1,8 +1,8 @@
 FROM node:9.4.0-alpine
-COPY app.js .
 COPY package.json .
 RUN npm install &&\
     apk update &&\
     apk upgrade
+COPY app.js .
 EXPOSE  8080
 CMD node app.js

Lab 3/watson-talk/Dockerfile

@@ -1,8 +1,8 @@
 FROM node:9.4.0-alpine
-COPY app.js .
 COPY package.json .
 RUN npm install &&\
     apk update &&\
     apk upgrade
+COPY app.js .
 EXPOSE  8080
 CMD node app.js

Lab 3/watson/Dockerfile

@@ -1,8 +1,8 @@
 FROM node:9.4.0-alpine
-COPY app.js .
 COPY package.json .
 RUN npm install &&\
     apk update &&\
     apk upgrade
+COPY app.js .
 EXPOSE  8080
 CMD node app.js