[CE-318] Fix user-dashboard image build fail

Downgrade node version to 8.9 to fix build user dashboard image error.

Change-Id: Ifcf266fb5b5058159679cd994701e042943c9dac
Signed-off-by: Haitao Yue <hightall@me.com>

dockerhub/latest/user-dashboard/Dockerfile

@@ -2,31 +2,31 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 #
-FROM node:9.2 as build_login
+FROM node:8.9 as build_login
 MAINTAINER haitao yue "hightall@me.com"
 RUN cd /tmp && git clone https://github.com/hyperledger/cello.git
 RUN cp -r /tmp/cello/user-dashboard/js /app
 RUN mkdir -p /usr/app
 RUN cp -r /tmp/cello/user-dashboard /usr/app/src
 RUN cd /app && npm install --loglevel http && npm run build
 
-FROM node:9.2 as build_home
+FROM node:8.9 as build_home
 MAINTAINER haitao yue "hightall@me.com"
 RUN cd /tmp && git clone https://github.com/hyperledger/cello.git
 RUN cp -r /tmp/cello/user-dashboard/js /app
 RUN mkdir -p /usr/app
 RUN cp -r /tmp/cello/user-dashboard /usr/app/src
 RUN cd /app/home && npm install --loglevel http && npm run build
 
-FROM node:9.2 as build_dashboard
+FROM node:8.9 as build_dashboard
 MAINTAINER haitao yue "hightall@me.com"
 RUN cd /tmp && git clone https://github.com/hyperledger/cello.git
 RUN cp -r /tmp/cello/user-dashboard/js /app
 RUN mkdir -p /usr/app
 RUN cp -r /tmp/cello/user-dashboard /usr/app/src
 RUN cd /app/dashboard && npm install --loglevel http && npm run build
 
-FROM node:9.2
+FROM node:8.9
 MAINTAINER haitao yue "hightall@me.com"
 RUN npm install -g requirejs
 RUN cd /tmp && git clone https://github.com/hyperledger/cello.git

user-dashboard/Dockerfile

@@ -3,7 +3,7 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 #
-FROM node:9.2
+FROM node:8.9
 MAINTAINER haitao yue "hightall@me.com"
 RUN npm install -g requirejs
 COPY package.json /