use parallel number:16.

.travis.yml

@@ -1,6 +1,6 @@
 language: ruby
 
-bundler_args: '-j32' # avoid travis-ci to set deployment mode by default, and use parallel bundlerr
+bundler_args: '-j16' # avoid travis-ci to set deployment mode by default, and use parallel bundlerr
 
 #before_script: bundle install