Merge pull request #355 from libgit2/cmn/travis-branches

travis: only build master and next
diff --git a/.travis.yml b/.travis.yml
index 79ad168..8a81f16 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -17,3 +17,8 @@
 matrix:
   allow_failures:
     - go: tip
+
+branches:
+  only:
+  - master
+  - next