Trying to fix Travis build for Node 5.*

.travis.yml

@@ -1,10 +1,18 @@
 language: node_js
 sudo: false
 node_js:
-    - "5.8"
-    - "0.12"
+  - "5.8"
+  - "0.12"
+env:
+  - CXX=g++-4.8
+addons:
+  apt:
+    sources:
+      - ubuntu-toolchain-r-test
+    packages:
+      - g++-4.8
 before_install:
-    - "npm install -g npm"
-    - "npm install -g grunt-cli"
+  - "npm install -g npm"
+  - "npm install -g grunt-cli"
 install:
-    - "npm install"
+  - "npm install"