Add travis build for ABI 46 and 47

Author: kevinmehall

.travis.yml

@@ -7,6 +7,8 @@ env:
   - NODE_VERSION="iojs-2.5.0"
   - NODE_VERSION="iojs-3.3.1"
   - NODE_VERSION="4.1"
+  - NODE_VERSION="4.2"
+  - NODE_VERSION="5.0"
   global:
     secure: VwwHS3ZYxu5WudTcWRw588aekYZrTHMDvziNWLhPnadVs+ami6EF7CMHFZenkvSehmmaunKaH0vcNuxDXqLjrZN8Qt6aOuVVq9o/N6+8OG6/E2D0lDRFF9OZdAKetzS7EtoZfVJpqe009leg9V5mjx3uo1WRlc6SqmeKynaUDaY=