Safely update npm to the latest supported version

lukechilds · lukechilds · commit 8d99ddaa8861 · 2019-04-09T15:40:21.000+07:00
diff --git a/.travis.yml b/.travis.yml
@@ -1,4 +1,6 @@
 language: node_js
+before_install:
+  - nvm install-latest-npm
 matrix:
   include:
   - node_js: '0.8'
