Update node version on circle

Tom Kirkpatrick · Tom Kirkpatrick · commit 37597bfc770e · 2016-07-10T20:01:26.000+02:00
diff --git a/circle.yml b/circle.yml
@@ -1,3 +1,6 @@
+machine:
+  node:
+    version: 6.1.0
 test:
   post:
     - npm run coverage
