.travis.yml in benchmark_driver-0.12.0 vs .travis.yml in benchmark_driver-0.13.0

- old
+ new

@@ -6,8 +6,11 @@
   - 2.5.0
 cache: bundler
 branches:
   only:
     - master
-before_install: gem install bundler -v 1.15.4
+before_install:
+  - gem install bundler -v 1.15.4
+  - gem install haml -v 4.0.7
+  - gem install haml -v 5.0.4
 script:
   - RSPEC_RETRIES=3 VERBOSE=1 bundle exec rake