Bump to NodeJS 10.x

Upgrade to NodeJS 10.x because WCT has dependencies that are
no more compatible with the legacy NodeJS 6.x

Change-Id: I2a78eaf179f174e65b533500eec3d44af2f95f45
diff --git a/jenkins-docker/slave-debian/Dockerfile b/jenkins-docker/slave-debian/Dockerfile
index facfd23..b375b4b 100644
--- a/jenkins-docker/slave-debian/Dockerfile
+++ b/jenkins-docker/slave-debian/Dockerfile
@@ -59,7 +59,7 @@
 
 # Node JS for PolyGerrit build
 
-RUN curl -sL https://deb.nodesource.com/setup_6.x | bash -
+RUN curl -sL https://deb.nodesource.com/setup_10.x | bash -
 RUN apt-get update && apt-get install -y nodejs
 
 # PolyGerrit tests
@@ -75,7 +75,7 @@
 COPY wct.conf.json /home/jenkins/
 RUN chown jenkins:jenkins /home/jenkins/wct.conf.json
 
-RUN npm install -g eslint@"=4.19.0" eslint-config-google eslint-plugin-html typescript fried-twinkie@">0.2.0" polylint polymer-cli web-component-tester
+RUN npm install --unsafe-perm -g eslint@"=4.19.0" eslint-config-google eslint-plugin-html typescript fried-twinkie@">0.2.0" polylint polymer-cli web-component-tester
 
 # Allow Android SDK tools to run on a 64-bit system, see
 # http://stackoverflow.com/a/23201209/1127485