.travis.yml in dry-struct-0.6.0 vs .travis.yml in dry-struct-0.7.0

@@ -2,23 +2,24 @@
 dist: trusty
 sudo: required
 bundler_args: --without benchmarks tools
 script:
   - bundle exec rake spec
-before_install:
-  - gem update --system
 after_success:
   - '[ -d coverage ] && bundle exec codeclimate-test-reporter'
 rvm:
-  - 2.2.10
-  - 2.3.7
-  - 2.4.4
-  - 2.5.1
-  - jruby-9.2.0.0
+  - 2.4.5
+  - 2.5.3
+  - 2.6.1
+  - jruby-9.2.6.0
+  - truffleruby
 env:
   global:
     - COVERAGE=true
     - JRUBY_OPTS='--dev -J-Xmx1024M'
+matrix:
+  allow_failures:
+    - rvm: truffleruby
 notifications:
   email: false
   webhooks:
     urls:
       - https://webhooks.gitter.im/e/19098b4253a72c9796db