.travis.yml in neo-dci-0.5.1 vs .travis.yml in neo-dci-0.6.0

@@ -1,18 +1,16 @@
 language: ruby
 sudo: false
 cache: bundler
 rvm:
   - ruby-head
-  - 2.3.1
-  - 2.2
-  - 2.1
+  - 2.7.0
+  - 2.6
+  - 2.5
   - jruby
   - jruby-head
-  - rbx-2
 matrix:
   allow_failures:
-    - rvm: rbx-2
     - rvm: jruby
     - rvm: jruby-head
     - rvm: ruby-head
 env:
   global: