[ci] use node 4.2 to test and do not allow failures

Author: jcrugzz

.travis.yml

@@ -3,7 +3,7 @@ language: node_js
 node_js:
   - "0.10"
   - "0.12"
-  - "4.1"
+  - "4.2"
 
 before_install:
   - travis_retry npm install -g [email protected]
@@ -12,10 +12,6 @@ before_install:
 script:
   - npm test
 
-matrix:
-  allow_failures:
-    - node_js: "4.1"
-
 notifications:
   email:
     - [email protected]