Make JS lint & test run on Travis (#2894)

* Make JS lint & test run on Travis

* Update node version required

* 6, any latest node 6

* Travis node_version

* query node & npm versions

* last attempt, use nvm directly

js/scripts/install-deps.sh

@@ -6,6 +6,8 @@ cd ..
 
 # install deps and store the exit code
 EXITCODE=0
+node --version
+npm --version
 npm install --progress=false || EXITCODE=1
 
 # back to root