chore(travis): Limit branches built to master and PRs

Kent C. Dodds · Kent C. Dodds · commit 25d640c182f6 · 2015-09-04T08:56:49.000-06:00
We don't need every release and other branches built.
diff --git a/.travis.yml b/.travis.yml
@@ -3,6 +3,9 @@ language: node_js
 cache:
   directories:
     - node_modules
+branches:
+  only:
+    - master
 notifications:
   email: false
 node_js:
