Update infrastructure

Author: robertodr

.travis.yml

@@ -3,8 +3,10 @@ sudo: false
 dist: trusty
 os: linux
 ruby: 2.2.0
-before_script:
-- pip intall yapf
+cache:
+  - pip
+  - bundler
+install:
 - bundle install
 script:
 - bundle exec danger

Dangerfile

@@ -18,5 +18,5 @@ if git.commits.any? { |c| c.message =~ /^Merge branch '#{github.branch_for_base}
   fail('Please rebase to get rid of the merge commits in this PR')
 end
 
-code_style_validation.check validator: ['yapf'],
-                            file_extensions: ['.py'] 
+code_style_validation.check validator: 'yapf',
+                            file_extensions: ['.py']

Gemfile.lock

@@ -1,9 +1,9 @@
 GIT
   remote: https://github.com/robertodr/danger-code_style_validation.git
-  revision: c5041a93b0e29957f6a26167164fcd320c88cf8b
+  revision: de63c3daee20a8611a6216ac35e77327eba5cd50
   branch: yapf
   specs:
-    danger-code_style_validation (0.1.0)
+    danger-code_style_validation (0.2.0)
       danger-plugin-api (~> 1.0)
 
 GEM