THRIFT-4343: enable nodejs-8.x on ubuntu-artful image and update grunt-jsdoc
also fix a perl failure as we were using a deprecated language feature
in the cross test server for perl.
Client: nodejs, perl

This closes #1406
diff --git a/build/docker/ubuntu-artful/Dockerfile b/build/docker/ubuntu-artful/Dockerfile
index 1c8f963..523fc36 100644
--- a/build/docker/ubuntu-artful/Dockerfile
+++ b/build/docker/ubuntu-artful/Dockerfile
@@ -46,8 +46,7 @@
 #     echo "deb [arch=amd64] https://packages.microsoft.com/repos/microsoft-ubuntu-xenial-prod xenial main" > /etc/apt/sources.list.d/dotnetdev.list
 
 # node.js (this step runs apt-get update internally) - if we ever want a later version
-# note: node 8.5 introduced some issues with directory handling / jsdoc / something... using 7.x for now
-# RUN curl -sL https://deb.nodesource.com/setup_7.x | bash
+RUN curl -sL https://deb.nodesource.com/setup_8.x | bash -
 
 ### install general dependencies
 RUN apt-get install -y --no-install-recommends \
@@ -170,8 +169,7 @@
 
 RUN apt-get install -y --no-install-recommends \
 `# Node.js dependencies` \
-      nodejs \
-      npm
+      nodejs
 
 RUN apt-get install -y --no-install-recommends \
 `# OCaml dependencies` \