.travis.yml in carrierwave-aliyun-0.5.1 vs .travis.yml in carrierwave-aliyun-0.7.0

@@ -1,8 +1,7 @@
 language: ruby
 bundler_args: --without development
 
 rvm:
   - 2.3.0
-  - 2.1.8
 
 script: rspec spec