.travis.yml in dry-struct-0.3.1 vs .travis.yml in dry-struct-0.4.0

@@ -5,10 +5,9 @@
 script:
   - bundle exec rake spec
 after_success:
   - '[ -d coverage ] && bundle exec codeclimate-test-reporter'
 rvm:
-  - 2.1.10
   - 2.2.7
   - 2.3.3
   - 2.4.1
   - jruby-9.1.10.0
 env: