Update TravisCI ruby version

Amir Tocker · Amir Tocker · commit 7f7a1604b048 · 2019-07-11T18:14:27.000+03:00
diff --git a/.travis.yml b/.travis.yml
@@ -4,6 +4,6 @@ before_install:
   - gem install bundler
 
 rvm:
-- 1.9.3
+- 1.9.3-p551
 - ruby-head
 script: bundle exec rspec
