Update .travis.yml

cheton · cheton · commit 642e8849a62f · 2016-11-28T15:50:00.000+08:00
diff --git a/.travis.yml b/.travis.yml
@@ -12,6 +12,10 @@ node_js:
   - '5'
   - '4'
 
+before_install:
+  - npm install -g npm
+  - npm --version
+
 after_success:
   - npm run coveralls
   - npm run coverage-clean
