Attempt Travis matrix build to run JS in addition to R tests

Author: alandipert

.travis.yml

@@ -1,8 +1,11 @@
-# R for travis: see documentation at https://docs.travis-ci.com/user/languages/r
-
-language: R
-sudo: required
-cache: packages
-
-before_install:
-  - sudo apt-get install -y libv8-dev
+matrix:
+  include:
+    # R for travis: see documentation at https://docs.travis-ci.com/user/languages/r
+    - language: R
+      sudo: required
+      cache: packages
+      before_install:
+        - sudo apt-get install -y libv8-dev
+    - language: node_js
+      addons:
+        - chrome: stable