.travis.yml in docbase-1.0.1 vs .travis.yml in docbase-2.0.0

@@ -1,10 +1,6 @@
 language: ruby
 rvm:
-  - 2.0
-  - 2.1
-  - 2.2
-  - 2.3
   - 2.4
   - 2.5
   - 2.6
   - ruby-head