pin down iojs version for travis ci

yyx990803 · yyx990803 · commit 7defa088d29d · 2015-06-12T14:23:09.000-04:00
diff --git a/.travis.yml b/.travis.yml
@@ -1,6 +1,6 @@
 language: node_js
 node_js:
-- "iojs"
+- "iojs-v2.0.1"
 branches:
   only:
   - master
