combine functions for easier maintenance.

.docker/Dockerfile.alpine

@@ -63,7 +63,7 @@ USER node-red
 
 # package.json contains Node-RED NPM module and node dependencies
 COPY package.json /usr/src/node-red/
-RUN npm install
+RUN npm install -g npm@next
 
 # Replace Python 2.7 with 3.6 in 36-rpi-gpio.js or remove Node-RED build-in rpi-gpio for non arm32v6
 USER root

.travis.yml

@@ -59,13 +59,10 @@ before_script:
     # Set BUILD_VERSION
     - if [ ! -z "${TRAVIS_TAG}" ]; then export BUILD_VERSION=${TRAVIS_TAG:1}; else export BUILD_VERSION=beta; fi
 
-    # Set Node-RED version
+    # Set NODE_RED_VERSION
     - >
       export NODE_RED_VERSION=$(grep -Eo "\"node-red\": \"(\w*.\w*.\w*)" package.json | cut -d\" -f4)
 
-    # Update NODE_RED_VERSION from package.json
-    #- ./.docker/update_version.sh
-
 script:
   # Build Docker image
   - ./.docker/docker.sh build