CI: run vint with reviewdog

.travis.yml

@@ -1,10 +1,15 @@
 language: ruby
 rvm:
     - 2.0.0
+install:
+    - git clone https://github.com/kana/vim-vspec.git
+    - pip install vim-vint --user
+    - go env
+    - go get -u github.com/haya14busa/reviewdog/cmd/reviewdog
 before_script:
     - bundle install
     - bundle show
 script:
+    - >-
+      vint plugin autoload/EasyMotion.vim autoload/EasyMotion/ | reviewdog -name=vint -efm="%f:%l:%c: %m" -reporter=github-pr-check
     - rake ci
-install:
-    - git clone https://github.com/kana/vim-vspec.git