Fix travis build

PiperOrigin-RevId: 313827636
diff --git a/.travis.yml b/.travis.yml
index 62ba0fb..e8b7dc3 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,8 +5,7 @@
 
 before_install:
   - brew tap bazelbuild/tap
-  - brew tap-pin bazelbuild/tap
-  - brew install bazel
+  - brew install bazelbuild/tap/bazel
 
 script:
   - bazel version