chore(build): Cache yarn & add node 7

STRML · STRML · commit 8a0175145567 · 2016-12-19T12:05:10.000-06:00
diff --git a/.travis.yml b/.travis.yml
@@ -1,5 +1,8 @@
 language: node_js
 node_js:
   - "6"
+  - "7"
 script:
   - make build test
+cache: yarn
+
