[Tests] fix syntax error in travis config

Fixes #250

Author: ljharb

.travis.yml

@@ -2,6 +2,7 @@ sudo: false
 language: node_js
 matrix:
   include:
+    - node_js: '4'
       env: TEST_SUITE=browser BROWSER_NAME=ie BROWSER_VERSION="10..latest"
     - node_js: '4'
       env: TEST_SUITE=browser BROWSER_NAME=chrome BROWSER_VERSION="-2..beta"